WorksheetsGEM 9.01
Total questions: 180
Worksheet time: 2hrs 30mins
Name
Class
Date
1.
Which mechanism best explains the antiviral activity of aciclovir?
a)
Competitive inhibition of viral neuraminidase
b)
Chain termination after incorporation by viral DNA polymerase
c)
Direct inhibition of viral protease
d)
Blockade of viral attachment to CD4 receptors
e)
Hypermutation of viral RNA genome
2.
Why is aciclovir selectively active in herpesvirus-infected cells?
a)
Preferential uptake by infected neurons
b)
Activation by host RNA polymerase
c)
Initial phosphorylation by viral thymidine kinase
d)
Higher affinity for viral ribosomes
e)
Reduced renal clearance in infected tissue
3.
A patient with suspected herpes simplex encephalitis requires treatment. Which is most appropriate?
a)
Oral valaciclovir
b)
Oral aciclovir
c)
IV aciclovir
d)
IV ganciclovir
e)
Oral famciclovir
4.
Which mutation most commonly causes aciclovir resistance?
a)
Viral neuraminidase mutation
b)
Loss or alteration of viral thymidine kinase
c)
Host DNA polymerase mutation
d)
Increased viral protease activity
e)
Reduced host cell uptake
5.
Which drug requires phosphorylation by the CMV UL97 enzyme?
a)
Aciclovir
b)
Cidofovir
c)
Ganciclovir
d)
Foscarnet
e)
Letermovir
6.
A CMV-infected bone marrow transplant patient develops severe neutropenia on treatment. Which antiviral is most likely responsible?
a)
Foscarnet
b)
Cidofovir
c)
Ganciclovir
d)
Letermovir
e)
Ribavirin
7.
Which antiviral acts by preventing release of influenza virions from host cells?
a)
Amantadine
b)
Ribavirin
c)
Oseltamivir
d)
Remdesivir
e)
Paxlovid
8.
Which antiviral is most limited by drug--drug interactions?
a)
Remdesivir
b)
Molnupiravir
c)
Oseltamivir
d)
Paxlovid
e)
Ribavirin
9.
Which COVID-19 treatment works by inhibiting viral protease activity?
a)
Remdesivir
b)
Molnupiravir
c)
Paxlovid
d)
Monoclonal antibodies
e)
Interferon-α
10.
Which statement best describes virus-specific T-cell therapy?
a)
First-line treatment for influenza
b)
Passive antibody transfer
c)
Expansion of patient T-cells targeting viral antigens
d)
Replacement for antiviral drugs
e)
Primarily used in immunocompetent hosts
11.
A CMV viral load continues to rise despite adequate dosing of ganciclovir. Genotyping shows a UL97 mutation. Which antiviral is the most appropriate next step?
a)
Foscarnet
b)
Valaciclovir
c)
Aciclovir
d)
Ribavirin
e)
Letermovir
12.
Which property most explains the improved oral bioavailability of valaciclovir compared with aciclovir?
a)
Reduced renal clearance
b)
Increased CNS penetration
c)
Addition of a valine ester side chain
d)
Higher affinity for viral DNA polymerase
e)
Resistance to thymidine kinase mutations
13.
Which antiviral exerts its effect at the viral DNA packaging stage, rather than synthesis?
a)
Ganciclovir
b)
Cidofovir
c)
Foscarnet
d)
Letermovir
e)
Ribavirin
14.
A renal transplant recipient develops CMV disease but has advanced chronic kidney disease. Which antiviral is least appropriate?
a)
Ganciclovir
b)
Valganciclovir
c)
Letermovir
d)
Ribavirin
e)
Cidofovir
15.
Which antiviral is most likely to cause seizures and reduced GCS in an elderly patient with acute kidney injury?
a)
Oseltamivir
b)
Aciclovir
c)
Molnupiravir
d)
Paxlovid
e)
Ribavirin
16.
Which antiviral mechanism best explains the activity of molnupiravir against SARS-CoV-2?
a)
Protease inhibition
b)
Neuraminidase inhibition
c)
RNA chain termination
d)
Blockade of ACE2 binding
e)
Induction of lethal mutagenesis
17.
Which factor most limits the long-term effectiveness of monoclonal antibodies against COVID-19?
a)
Poor tissue penetration
b)
Viral spike protein mutation
c)
High rates of infusion reactions
d)
Requirement for IV administration
e)
Limited antibody half-life
18.
Which antiviral was historically important for hepatitis C but is now rarely used due to toxicity and poor efficacy?
a)
Sofosbuvir
b)
Interferon-α
c)
Ribavirin
d)
Ledipasvir
e)
Velpatasvir
19.
Which antiviral remains effective against avian influenza (e.g. H5N1)?
a)
Amantadine
b)
Ribavirin
c)
Remdesivir
d)
Oseltamivir
e)
Molnupiravir
20.
Which scenario best justifies the use of virus-specific T-cell therapy?
a)
Healthy adult with shingles
b)
Pregnant woman with RSV
c)
Elderly patient with influenza
d)
Mild CMV viraemia
e)
Post–bone marrow transplant patient with refractory CMV
21.
Which feature of HIV replication most directly explains the rapid development of drug resistance?
a)
Integration into host DNA
b)
High viral load during seroconversion
c)
Error-prone reverse transcriptase
d)
Latent infection in CD4 cells
e)
Glycoprotein-mediated cell entry
22.
A patient presents with flu-like symptoms, rash, and lymphadenopathy 3 weeks after high-risk sexual exposure. Which laboratory finding is most likely at this stage?
a)
Undetectable viral load
b)
Positive HIV antibody test only
c)
Low CD4 count (<200 cells/µL)
d)
Detectable HIV p24 antigen
e)
Opportunistic fungal infection
23.
Which CD4 count is most strongly associated with Pneumocystis jirovecii pneumonia?
a)
>600 cells/µL
b)
400–500 cells/µL
c)
200–350 cells/µL
d)
<200 cells/µL
e)
Any CD4 count
24.
Which HIV enzyme is targeted by drugs ending in "-gravir"?
a)
Protease
b)
Reverse transcriptase
c)
Integrase
d)
gp120
e)
CCR5 receptor
25.
Which statement best describes HIV-2 compared with HIV-1?
a)
More transmissible globally
b)
More pathogenic
c)
Restricted mainly to West Africa
d)
Causes faster progression to AIDS
e)
Resistant to antiretroviral therapy
26.
A patient with well-controlled HIV (undetectable viral load) wishes to conceive with an HIV-negative partner. What is the most accurate advice?
a)
Transmission risk remains high
b)
Conception should be avoided
c)
Barrier contraception is mandatory
d)
HIV transmission risk is effectively zero
e)
Partner must start post-exposure prophylaxis
27.
Which mechanism best explains how NRTIs inhibit HIV replication?
a)
Blocking viral entry
b)
Inhibiting integrase binding
c)
Causing premature DNA chain termination
d)
Preventing viral budding
e)
Neutralising circulating virions
28.
Which imaging feature most strongly suggests Pneumocystis pneumonia rather than COVID-19 pneumonitis?
a)
Peripheral ground-glass opacities
b)
Central ground-glass opacities with peripheral sparing
c)
Lobar consolidation
d)
Pleural effusion
e)
Cavitating lesions
29.
Which strategy has most reduced mother-to-child HIV transmission in the UK?
a)
Caesarean delivery for all HIV-positive mothers
b)
Avoidance of breastfeeding alone
c)
Antiretroviral therapy during pregnancy
d)
Neonatal vaccination
e)
Maternal antibody screening only
30.
Which factor most strongly predicts rapid progression to AIDS in untreated HIV?
a)
Route of transmission
b)
Age at infection
c)
Initial viral set-point
d)
Presence of antibodies
e)
Viral subtype
31.
A patient with newly diagnosed HIV has a high viral load and a CD4 count of 520 cells/µL. He feels well. What is the strongest rationale for starting antiretroviral therapy immediately?
a)
Reduction of long-term inflammatory and cardiovascular risk
b)
Prevention of seroconversion illness
c)
Elimination of latent viral reservoirs
d)
Avoidance of false-negative antibody tests
e)
Reduction of drug resistance development
32.
Which characteristic best explains why integrase inhibitors are favoured in first-line HIV therapy?
a)
Superior penetration into latent reservoirs
b)
High genetic barrier to resistance
c)
Ability to eradicate proviral DNA
d)
Reduced need for adherence
e)
Activity against HIV-2 only
33.
A patient has repeatedly undetectable HIV viral loads without antiretroviral therapy. Which mechanism most plausibly explains this finding?
a)
Reduced CCR5 receptor expression due to medication
b)
Infection with HIV-2
c)
Host immune-mediated viral suppression
d)
Laboratory assay insensitivity
e)
Prior post-exposure prophylaxis
34.
Which step in the HIV life cycle is directly targeted by protease inhibitors?
a)
Viral entry into CD4 cells
b)
Reverse transcription
c)
Integration into host genome
d)
Maturation of viral particles
e)
Budding from host cell membrane
35.
A clinician prescribes oral midazolam to a patient taking a protease inhibitor. What is the most serious potential consequence?
a)
Reduced benzodiazepine efficacy
b)
Increased viral replication
c)
Acute withdrawal symptoms
d)
Loss of antiretroviral effectiveness
e)
Life-threatening respiratory depression
36.
Which finding most strongly supports a diagnosis of advanced HIV rather than acute infection?
a)
Oral candidiasis
b)
High plasma viral load
c)
Generalised lymphadenopathy
d)
Flu-like illness
e)
Detectable p24 antigen
37.
Why does intermittent adherence to ART accelerate treatment failure?
a)
Increased antibody neutralisation
b)
Selective expansion of resistant viral subpopulations
c)
Enhanced viral latency
d)
Reduced CD4 receptor expression
e)
Increased host immune tolerance
38.
Which diagnostic strategy minimises missed early HIV infection?
a)
Antibody-only testing at 6 weeks
b)
CD4 count measurement
c)
Fourth-generation antigen/antibody assay
d)
Viral culture
e)
Western blot only
39.
Which factor most reduces heterosexual HIV transmission rates in the UK currently?
a)
Reduced injecting drug use
b)
Increased condom use
c)
Partner notification programmes
d)
Widespread viral suppression with ART
e)
Routine antenatal screening
40.
Why has HIV vaccination remained elusive despite decades of research?
a)
Lack of animal models
b)
Inadequate antibody responses
c)
Poor T-cell activation
d)
Rapid clearance of vaccine antigens
e)
Extreme viral genetic diversity
41.
A 7-month-old boy has recurrent bacterial chest infections. Blood tests show absent circulating immunoglobulins and no mature B cells. Which defect most likely explains this condition?
a)
Failure of isotype class switching
b)
Absence of thymic epithelium
c)
Defective Bruton's tyrosine kinase
d)
CD40 ligand deficiency
e)
Increased IgM production
42.
Which infection is most characteristic of an isolated T-cell deficiency?
a)
Streptococcus pneumoniae pneumonia
b)
Haemophilus influenzae otitis media
c)
Pneumocystis jirovecii pneumonia
d)
Recurrent Neisseria meningitidis infection
e)
Giardia lamblia diarrhoea
43.
A patient has normal or raised IgM levels but very low IgG and IgA. What is the underlying immunological defect?
a)
Absence of plasma cells
b)
Failure of B-cell maturation
c)
Defective T-helper cell–mediated class switching
d)
Increased apoptosis of B cells
e)
Complement C3 deficiency
44.
Which feature most strongly suggests common variable immunodeficiency (CVID)?
a)
Absent B cells
b)
Isolated IgA deficiency
c)
Low IgG and IgA with recurrent bacterial infections
d)
Severe viral infections in infancy
e)
X-linked inheritance in neonates
45.
A child with facial abnormalities, hypocalcaemia, and recurrent viral infections is most likely to have impaired development of which organ?
a)
Bone marrow
b)
Spleen
c)
Thymus
d)
Tonsils
e)
Peyer patches
46.
Which cell surface receptor is essential for HIV entry into CD4⁺ T cells?
a)
CD8
b)
CD28
c)
gp41
d)
CD4
e)
MHC class II
47.
At what CD4⁺ T-cell count is AIDS diagnosed?
a)
<1000 cells/µL
b)
<750 cells/µL
c)
<500 cells/µL
d)
<350 cells/µL
e)
<200 cells/µL
48.
A neonate has severe bacterial, viral, and fungal infections with chronic diarrhoea and failure to thrive. What is the most likely diagnosis?
a)
DiGeorge syndrome
b)
Chronic granulomatous disease
c)
Hyper-IgM syndrome
d)
Severe combined immunodeficiency
e)
Kostmann syndrome
49.
Which condition results from defective neutrophil oxidative burst?
a)
Kostmann syndrome
b)
Cyclical neutropenia
c)
Chronic granulomatous disease
d)
SCID
e)
CVID
50.
Recurrent Neisseria infections are most strongly associated with deficiency of which immune component?
a)
IgA
b)
CD8⁺ T cells
c)
Complement membrane attack complex
d)
Neutrophil elastase
e)
CD40 ligand
51.
A patient with recurrent sinopulmonary infections has normal B-cell numbers but profoundly reduced IgG and IgA. Which immunological process is most directly impaired?
a)
Cytokine-dependent immunoglobulin class switching
b)
V(D)J recombination
c)
B-cell negative selection
d)
Plasma cell survival
e)
Fc receptor expression
52.
Which clinical feature best differentiates severe combined immunodeficiency (SCID) from isolated antibody deficiency?
a)
Recurrent bacterial infections
b)
Persistent viral, fungal, and protozoal infections
c)
Low IgG levels
d)
Response to immunoglobulin replacement
e)
Recurrent otitis media
53.
Loss of which immune cell population most directly explains the increased incidence of Kaposi sarcoma in AIDS?
a)
B lymphocytes
b)
Neutrophils
c)
CD4⁺ T helper cells
d)
Natural killer cells
e)
Macrophages
54.
A child presents with recurrent bacterial and fungal infections. Neutrophil count is normal, but oxidative killing is impaired. Which mechanism is defective?
a)
Chemotaxis
b)
Complement activation
c)
Antibody opsonisation
d)
Phagolysosome respiratory burst
e)
Bone marrow neutrophil production
55.
Which immunodeficiency most strongly predisposes to immune-complex–mediated vascular damage?
a)
Bruton's agammaglobulinaemia
b)
Hyper-IgM syndrome
c)
CVID
d)
Neutrophil elastase deficiency
e)
Complement regulatory protein deficiency
56.
Which feature best explains why HIV persists despite effective antiretroviral therapy?
a)
Viral reservoirs in lymphoid tissue
b)
Rapid antibody neutralisation
c)
Complete eradication of CD8⁺ T cells
d)
Inability of HIV to mutate
e)
Loss of macrophage infection
57.
Which infection risk is most specifically increased when CD4⁺ T-cell counts fall below 200 cells/µL?
a)
Streptococcal pneumonia
b)
Pneumocystis jirovecii pneumonia
c)
Clostridioides difficile colitis
d)
Campylobacter enteritis
e)
Staphylococcal abscesses
58.
Which immunological abnormality best explains recurrent infections in X-linked agammaglobulinaemia?
a)
Failure of thymic selection
b)
Defective CD40 ligand expression
c)
Arrest at pre-B-cell stage
d)
Excessive neutrophil apoptosis
e)
Complement C5 deficiency
59.
Which feature best distinguishes DiGeorge syndrome from SCID?
a)
Early-onset severe infections
b)
Failure to thrive
c)
Absence of B cells
d)
Thymic hypoplasia with facial anomalies
e)
Fatal outcome without bone marrow transplant
60.
Which mechanism best explains susceptibility to Neisseria species in complement deficiency?
a)
Impaired opsonisation
b)
Reduced chemotaxis
c)
Decreased antibody affinity
d)
Failure of immune complex clearance
e)
Loss of membrane attack complex formation
61.
A flat, non-palpable skin lesion measuring 5 mm in diameter is most accurately described as which of the following?
a)
Papule
b)
Plaque
c)
Macule
d)
Vesicle
e)
Nodule
62.
Which epidermal cell type is primarily responsible for antigen presentation in the skin?
a)
Keratinocytes
b)
Melanocytes
c)
Merkel cells
d)
Langerhans cells
e)
Fibroblasts
63.
Which structure primarily prevents paracellular diffusion within the epidermis?
a)
Desmosomes
b)
Hemidesmosomes
c)
Tight junctions
d)
Basement membrane
e)
Keratin filaments
64.
A patient with chronic scratching develops thickened, hardened skin. What is the most appropriate term?
a)
Atrophy
b)
Scar
c)
Fissure
d)
Lichenification
e)
Erythema
65.
Which epidermal layer contains melanocytes?
a)
Stratum corneum
b)
Stratum lucidum
c)
Stratum granulosum
d)
Stratum spinosum
e)
Stratum basale
66.
Which component of the basement membrane is most responsible for structural support?
a)
Type I collagen
b)
Type IV collagen
c)
Elastin
d)
Keratin
e)
Melanin
67.
Which condition is most directly associated with separation at the epidermal-dermal junction?
a)
Psoriasis
b)
Impetigo
c)
Bullous pemphigoid
d)
Actinic keratosis
e)
Urticaria
68.
Which function of the skin is primarily responsible for reducing microbial colonisation?
a)
Melanin production
b)
Keratin synthesis
c)
Acidic mantle formation
d)
Vasoconstriction
e)
Sweat evaporation
69.
Which cell type makes up approximately 95% of epidermal cells?
a)
Melanocytes
b)
Langerhans cells
c)
Merkel cells
d)
Keratinocytes
e)
Fibroblasts
70.
Which skin cancer listed below is considered malignant?
a)
Actinic keratosis
b)
Seborrhoeic keratosis
c)
Melanoma
d)
Dermatofibroma
e)
Lipoma
71.
Failure of a skin lesion to remain confined to the epidermis most directly reflects dysfunction of which structure?
a)
Basement membrane
b)
Stratum corneum
c)
Tight junctions
d)
Keratin filaments
e)
Acidic mantle
72.
A painful linear crack in the skin of a patient with chronic xerosis is best described as which lesion type?
a)
Scar
b)
Fissure
c)
Ulcer
d)
Nodule
e)
Atrophy
73.
Which epidermal cell directly transduces mechanical stimuli into neural signals?
a)
Langerhans cell
b)
Keratinocyte
c)
Merkel cell
d)
Melanocyte
e)
Fibroblast
74.
Which process most directly explains the waterproofing function of the epidermis?
a)
Melanin synthesis
b)
Sweat evaporation
c)
Keratinocyte migration
d)
Phospholipid organisation
e)
Dermal vasodilation
75.
Which pathology most specifically arises from defective epidermal–dermal adhesion?
a)
Psoriasis
b)
Urticaria
c)
Impetigo
d)
Actinic keratosis
e)
Junctional epidermolysis bullosa
76.
Which layer of the skin contains the primary vascular supply?
a)
Epidermis
b)
Dermis
c)
Stratum corneum
d)
Stratum basale
e)
Hypodermis
77.
A raised, solid skin lesion measuring 7 mm is most accurately classified as which lesion?
a)
Macule
b)
Vesicle
c)
Papule
d)
Plaque
e)
Nodule
78.
Which factor most directly contributes to reduced microbial growth on healthy skin?
a)
Keratinocyte turnover
b)
Acidic pH
c)
Dermal immune cells
d)
Melanin concentration
e)
Epidermal thickness
79.
Which condition listed is an example of chronic skin inflammation?
a)
Urticaria
b)
Acute eczema
c)
Impetigo
d)
Psoriasis
e)
Warts
80.
Which pathological process best explains skin thinning following prolonged topical steroid use?
a)
Scar formation
b)
Lichenification
c)
Epidermal hyperplasia
d)
Increased keratinisation
e)
Atrophy
81.
A 72-year-old man presents with tense blisters on his abdomen and limbs, preceded by intense itching. Oral mucosa is spared. Which pathological process best explains this condition?
a)
Autoantibodies against desmosomes
b)
Autoantibodies against dermo-epidermal junction proteins
c)
Mutation of keratin genes
d)
Mutation of type VII collagen
e)
Immune complex deposition in superficial dermis
82.
Which blistering disorder is most strongly associated with coeliac disease?
a)
Bullous pemphigoid
b)
Pemphigus vulgaris
c)
Dermatitis herpetiformis
d)
Junctional epidermolysis bullosa
e)
Dystrophic epidermolysis bullosa
83.
A child develops superficial skin blisters after minor friction. Histology shows intra-epidermal blistering. Which protein defect is most likely?
a)
Collagen type VII
b)
Laminin
c)
Keratin
d)
Desmoglein
e)
Integrins
84.
Which feature best distinguishes dystrophic epidermolysis bullosa from epidermolysis bullosa simplex?
a)
Autosomal inheritance
b)
Blistering after friction
c)
Involvement of deeper skin layers
d)
Onset in childhood
e)
Epidermal separation
85.
Which histological finding is most characteristic of acute eczema?
a)
Loss of granular layer
b)
Neutrophils in stratum corneum
c)
Spongiosis
d)
Subepidermal blister
e)
Dermal fibrosis
86.
Chronic eczema most commonly leads to which structural skin change?
a)
Epidermal atrophy
b)
Elongated rete ridges
c)
Subepidermal clefting
d)
Loss of dermal collagen
e)
Reduced keratinisation
87.
Removal of thick white scales from a red plaque results in pinpoint bleeding. Which diagnosis is most likely?
a)
Chronic eczema
b)
Lichen planus
c)
Psoriasis
d)
Urticaria
e)
Erythema multiforme
88.
Which inflammatory infiltrate is most typical of psoriasis?
a)
Eosinophils in dermis
b)
Lymphocytes in basal layer
c)
Neutrophils in stratum corneum
d)
Plasma cells around vessels
e)
Mast cells in epidermis
89.
Which feature is most consistent with urticaria?
a)
Epidermal hyperplasia
b)
Subepidermal blistering
c)
Normal epidermis
d)
Elongated rete ridges
e)
Parakeratosis
90.
A patient develops symmetrical target-like lesions after a herpes simplex infection. Which diagnosis is most likely?
a)
Psoriasis
b)
Lichen planus
c)
Bullous pemphigoid
d)
Erythema multiforme
e)
Acute eczema
91.
A neonate has widespread blistering involving skin and internal organs. Histology shows separation at the basement membrane zone due to defective hemidesmosomes. Which diagnosis is most likely?
a)
Junctional epidermolysis bullosa
b)
Epidermolysis bullosa simplex
c)
Dystrophic epidermolysis bullosa
d)
Bullous pemphigoid
e)
Pemphigus vulgaris
92.
Which histological feature best differentiates chronic eczema from acute eczema?
a)
Spongiosis
b)
Dermal oedema
c)
Elongated rete ridges with fibrosis
d)
Dilated capillaries
e)
Epidermal vesicle formation
93.
A patient presents with intensely pruritic purple, flat-topped papules on wrists and oral mucosa. Which immunological mechanism underlies this condition?
a)
Immune complex deposition
b)
Autoantibodies to basement membrane
c)
T-cell-mediated cytotoxicity
d)
Neutrophil-driven inflammation
e)
Mast cell degranulation
94.
Which pathological feature explains why psoriasis plaques bleed when scales are removed?
a)
Loss of epidermal barrier
b)
Thinning of the dermis
c)
Dermal fibrosis
d)
Dilated capillaries in dermal papillae
e)
Epidermal blistering
95.
Which feature most reliably distinguishes bullous pemphigoid from pemphigus vulgaris?
a)
Presence of autoantibodies
b)
Blister formation
c)
Inflammatory infiltrate
d)
Age of onset
e)
Tense nature of blisters
96.
Which histological finding is most specific to psoriasis?
a)
Spongiotic vesicles
b)
Loss of granular layer with parakeratosis
c)
Subepidermal clefting
d)
Dense eosinophilic infiltrate
e)
Epidermal atrophy
97.
Which statement best explains the mechanism of blister formation in epidermolysis bullosa simplex?
a)
Autoimmune destruction of hemidesmosomes
b)
Separation at the dermo-epidermal junction
c)
Keratin cytoskeleton fragility
d)
Defective anchoring fibrils
e)
Immune complex deposition
98.
A patient develops transient erythematous plaques with dermal oedema after exposure to cold. The epidermis is normal. Which cell type is most involved?
a)
Neutrophils
b)
Lymphocytes
c)
Plasma cells
d)
Keratinocytes
e)
Eosinophils
99.
Which clinical scenario best suggests progression from acute to chronic eczema?
a)
Sudden vesicle eruption
b)
Recurrent wheals resolving in hours
c)
Painful mucosal erosions
d)
Target lesions on limbs
e)
Thickened hyperpigmented skin with exaggerated markings
100.
Which feature increases the likelihood that erythema multiforme is classified as major rather than minor?
a)
Symmetrical distribution
b)
Target lesion morphology
c)
Intense pruritus
d)
Trigger by herpes simplex
e)
Mucosal involvement
101.
A child presents with honey-coloured crusted lesions around the mouth. Which organism is most commonly responsible?
a)
Pseudomonas aeruginosa
b)
Staphylococcus aureus
c)
Cutibacterium acnes
d)
Mycobacterium leprae
e)
Candida albicans
102.
Which factor increases the risk of developing cellulitis?
a)
Vitiligo
b)
Lymphoedema
c)
Pregnancy
d)
Albinism
e)
Seborrhoeic keratosis
103.
Progression of uncontrolled cellulitis may lead to:
a)
Melanoma
b)
Basal cell carcinoma
c)
Necrotising fasciitis
d)
Actinic keratosis
e)
Seborrhoeic keratosis
104.
Which pathological feature best characterises dysplasia?
a)
Uniform nuclei and organised growth
b)
Increased melanin production
c)
Irregular nuclear shape
d)
Loss of basement membrane
e)
Keratin plug formation
105.
Which skin cancer is most strongly associated with cumulative sun exposure and rarely metastasises?
a)
Squamous cell carcinoma
b)
Melanoma
c)
Basal cell carcinoma
d)
Seborrhoeic keratosis
e)
Dysplastic naevus
106.
A red, scaly, ulcerated lesion with raised borders on the lower lip is most suggestive of:
a)
Basal cell carcinoma
b)
Squamous cell carcinoma
c)
Melanoma
d)
Seborrhoeic keratosis
e)
Junctional naevus
107.
Which condition results from autoimmune destruction of melanocytes?
a)
Albinism
b)
Melasma
c)
Vitiligo
d)
Tinea versicolor
e)
Post-inflammatory hyperpigmentation
108.
Which type of naevus is located primarily within the dermis?
a)
Junctional
b)
Compound
c)
Dermal
d)
Dysplastic
e)
Congenital
109.
Which feature suggests a dysplastic naevus rather than a benign mole?
a)
Diameter <5 mm
b)
Symmetrical shape
c)
Uniform pigmentation
d)
Irregular borders
e)
Smooth surface
110.
A middle-aged patient has multiple brown, waxy lesions that appear "stuck on" the skin. What is the most likely diagnosis?
a)
Melanoma
b)
Basal cell carcinoma
c)
Squamous cell carcinoma
d)
Seborrhoeic keratosis
e)
Actinic keratosis
111.
A fair-skinned patient has a slowly enlarging pearly lesion on the nose with surface telangiectasia. Which property best explains why prognosis is usually excellent?
a)
Rarely metastasises
b)
Low mitotic index
c)
Occurs only in young patients
d)
Limited to the dermis
e)
Not related to UV exposure
112.
Which scenario most strongly increases the likelihood that a skin lesion represents squamous cell carcinoma rather than basal cell carcinoma?
a)
Pearly appearance
b)
History of chronic occupational sun exposure
c)
Occurrence on the trunk
d)
Lack of ulceration
e)
Presence of telangiectasia
113.
Which histological feature most strongly suggests progression from dysplasia toward malignancy?
a)
Increased melanin production
b)
Uniform nuclear staining
c)
Disorganised cellular architecture
d)
Reduced cell replication
e)
Preservation of normal polarity
114.
Which lesion carries the highest risk of malignant transformation?
a)
Dermal naevus
b)
Junctional naevus
c)
Compound naevus
d)
Dysplastic naevus
e)
Seborrhoeic keratosis
115.
Which mechanism best explains post-inflammatory hyperpigmentation?
a)
Autoimmune melanocyte destruction
b)
Genetic absence of melanin
c)
Fungal inhibition of melanocytes
d)
Reduced melanosome transfer
e)
Increased melanin production after injury
116.
A lesion appears flat, uniformly pigmented, and located at the epidermal-dermal junction. Which diagnosis fits best?
a)
Junctional naevus
b)
Dermal naevus
c)
Compound naevus
d)
Dysplastic naevus
e)
Seborrhoeic keratosis
117.
Which condition may cause either hypopigmented or hyperpigmented patches on the trunk?
a)
Vitiligo
b)
Tinea versicolor
c)
Melasma
d)
Albinism
e)
Post-inflammatory pigmentation
118.
Which feature best distinguishes seborrhoeic keratosis from malignant skin lesions?
a)
Irregular borders
b)
Pigment variation
c)
"Stuck-on" waxy appearance
d)
Rapid growth
e)
Ulceration
119.
Which factor most strongly links basal cell carcinoma to anatomical site distribution?
a)
Melanocyte density
b)
Hair follicle concentration
c)
Immune surveillance
d)
Cumulative UV exposure
e)
Genetic mutation alone
120.
Which combination of features is most concerning for melanoma development?
a)
Small, symmetrical, uniform naevus
b)
Raised dermal naevus
c)
Congenital mole without change
d)
Flat junctional naevus
e)
Large asymmetrical mole with colour variation
121.
Which cell type gives rise to melanoma?
a)
Keratinocytes
b)
Langerhans cells
c)
Melanocytes
d)
Fibroblasts
e)
Endothelial cells
122.
Which melanoma subtype is most common?
a)
Nodular malignant melanoma
b)
Lentigo malignant melanoma
c)
Superficial spreading melanoma
d)
Thin malignant melanoma
e)
Acral lentiginous melanoma
123.
Vertical invasion of the dermis is most characteristic of which melanoma?
a)
Superficial spreading melanoma
b)
Nodular malignant melanoma
c)
Lentigo malignant melanoma
d)
Thin malignant melanoma
e)
In situ melanoma
124.
Which ABCDE feature assesses uneven halves of a lesion?
a)
Border
b)
Colour
c)
Diameter
d)
Evolution
e)
Asymmetry
125.
Which border feature most suggests melanoma?
a)
Smooth and well-defined edge
b)
Symmetrical outline
c)
Sharp demarcation from skin
d)
Notched or blurred margins
e)
Uniform pigmentation at edge
126.
Which colour pattern is most concerning for melanoma?
a)
Uniform light brown
b)
Even tan pigmentation
c)
Multiple shades within one lesion
d)
Skin-coloured papule
e)
Pale pink macule
127.
A mole measuring 7 mm in diameter is best interpreted how?
a)
Diagnostic of melanoma
b)
Benign if symmetrical
c)
Requires assessment with other features
d)
Normal variant
e)
Suggests squamous cell carcinoma
128.
Which factor most strongly increases melanoma risk?
a)
Chronic eczema
b)
Repeated UV exposure
c)
Poor diet
d)
Diabetes mellitus
e)
Psoriasis
129.
Which patient has the highest melanoma risk?
a)
Dark-skinned individual with freckles
b)
Young adult with acne
c)
Fair-skinned person with light eyes
d)
Patient with vitiligo
e)
Individual with seborrhoeic keratoses
130.
Which history increases risk of developing another melanoma?
a)
Previous basal cell carcinoma
b)
Family history of eczema
c)
Prior melanoma diagnosis
d)
Childhood chickenpox
e)
Atopic dermatitis
131.
Which feature best explains why melanoma is considered the most life-threatening skin cancer?
a)
Early metastatic potential
b)
High incidence in the population
c)
Frequent ulceration
d)
Association with chronic inflammation
e)
Pain at presentation
132.
Which melanoma subtype is most likely to present late due to initial lack of ABCDE features?
a)
Superficial spreading melanoma
b)
Nodular malignant melanoma
c)
Lentigo malignant melanoma
d)
Thin malignant melanoma
e)
Melanoma in situ
133.
A changing mole becomes asymmetric over several months. Which ABCDE principle best explains this progression?
a)
Asymmetry is required at onset
b)
Border irregularity precedes asymmetry
c)
Evolution allows late development of asymmetry
d)
Diameter change drives asymmetry
e)
Colour change prevents symmetry
134.
Which finding best distinguishes malignant from benign borders on clinical examination?
a)
Raised edges
b)
Uniform pigmentation
c)
Clear demarcation
d)
Fading edge into surrounding skin
e)
Smooth curvature
135.
Which statement best reflects the limitation of diameter as a melanoma criterion?
a)
Diameter >6 mm excludes melanoma
b)
Smaller lesions are always benign
c)
Diameter alone is insufficient for diagnosis
d)
Diameter predicts metastatic spread
e)
Diameter determines melanoma subtype
136.
Which patient characteristic most directly increases UV-mediated DNA damage risk?
a)
Dark hair
b)
High melanin concentration
c)
Fair skin phenotype
d)
Thick epidermis
e)
Increased dermal collagen
137.
Which risk factor combination confers the highest cumulative melanoma risk?
a)
Male sex and psoriasis
b)
Prior melanoma and dysplastic moles
c)
Basal cell carcinoma and eczema
d)
Young age and acne
e)
Indoor occupation and vitamin D deficiency
138.
Why is melanoma more common on the back and legs?
a)
Higher melanocyte density
b)
Increased friction
c)
Continuous sun exposure
d)
Intermittent UV exposure
e)
Thinner epidermis
139.
Which demographic trend is most accurate regarding melanoma?
a)
More common in women under 30
b)
Equal prevalence across all ages
c)
Rare after age 50
d)
Predominantly affects immunocompetent children
e)
Higher prevalence in older men
140.
Which histological feature best supports a diagnosis of thin malignant melanoma?
a)
Extensive dermal invasion
b)
Absence of melanocytes
c)
Keratin pearl formation
d)
Pure epidermal involvement
e)
Micro-invasion with atypical melanocyte clumps
141.
A patient with untreated HIV has a CD4 count of 40 cells/µL. Which infection is MOST likely?
a)
Pneumocystis jirovecii pneumonia
b)
Cryptococcal meningitis
c)
Pulmonary tuberculosis
d)
Kaposi sarcoma
e)
Bacterial pneumonia
142.
Which feature most strongly supports Pneumocystis jirovecii pneumonia over bacterial pneumonia?
a)
Productive cough
b)
Lobar consolidation on chest X-ray
c)
Exertional desaturation
d)
High neutrophil count
e)
Positive blood cultures
143.
First-line treatment for moderate–severe Pneumocystis jirovecii pneumonia is:
a)
Oral azithromycin
b)
IV ceftriaxone
c)
High-dose co-trimoxazole plus steroids
d)
Inhaled pentamidine alone
e)
Fluconazole
144.
Primary prophylaxis against Pneumocystis jirovecii pneumonia should start when CD4 count falls below:
a)
500 cells/µL
b)
350 cells/µL
c)
250 cells/µL
d)
200 cells/µL
e)
50 cells/µL
145.
Which opportunistic infection commonly presents with ring-enhancing brain lesions?
a)
Progressive multifocal leukoencephalopathy
b)
Primary CNS lymphoma
c)
Cerebral toxoplasmosis
d)
Cryptococcal meningitis
e)
CMV encephalitis
146.
Which CD4 threshold is MOST associated with CMV retinitis?
a)
<350 cells/µL
b)
<200 cells/µL
c)
<150 cells/µL
d)
<100 cells/µL
e)
<50 cells/µL
147.
Which investigation best confirms a diagnosis of Pneumocystis jirovecii pneumonia?
a)
Blood cultures
b)
Serum beta-D-glucan
c)
Induced sputum PCR
d)
Chest X-ray
e)
HIV viral load
148.
Which opportunistic infection has no effective antimicrobial therapy, with treatment relying on immune reconstitution?
a)
Cryptosporidiosis
b)
CMV colitis
c)
Oesophageal candidiasis
d)
Toxoplasmosis
e)
Tuberculosis
149.
Which opportunistic infection is caused by JC virus?
a)
CMV encephalitis
b)
Cryptococcal meningitis
c)
Progressive multifocal leukoencephalopathy
d)
Cerebral toxoplasmosis
e)
Primary CNS lymphoma
150.
A patient with HIV develops violaceous skin plaques and oral lesions. The causative pathogen is:
a)
Epstein–Barr virus
b)
Human herpesvirus-6
c)
Human herpesvirus-8
d)
Cytomegalovirus
e)
Human papillomavirus
151.
A patient with advanced HIV presents with headache and fever. Lumbar puncture shows very high opening pressure. Which management step is MOST important acutely?
a)
Repeated therapeutic lumbar punctures
b)
Immediate initiation of antiretroviral therapy
c)
IV dexamethasone
d)
Empirical aciclovir
e)
Emergency craniotomy
152.
Which radiological feature most strongly suggests progressive multifocal leukoencephalopathy (PML)?
a)
Ring-enhancing lesions with mass effect
b)
Diffuse white matter changes without enhancement
c)
Basal meningeal enhancement
d)
Multiple abscesses with oedema
e)
Hydrocephalus
153.
Which opportunistic infection is MOST strongly associated with CD4 <100 cells/µL and subacute meningitis?
a)
CMV encephalitis
b)
TB meningitis
c)
Cryptococcal meningitis
d)
Neurosyphilis
e)
HIV seroconversion
154.
A patient with HIV and cerebral ring-enhancing lesions does not improve after 14 days of empiric toxoplasmosis treatment. What is the NEXT most appropriate step?
a)
Switch to IV ganciclovir
b)
Add corticosteroids
c)
Repeat toxoplasma serology
d)
Brain biopsy
e)
Start whole-brain radiotherapy
155.
Which opportunistic infection can present with bloody diarrhoea and shows inclusion bodies on colonic biopsy?
a)
Cryptosporidiosis
b)
Isosporiasis
c)
Microsporidiosis
d)
Shigellosis
e)
CMV colitis
156.
Which infection may worsen transiently after starting antiretroviral therapy due to immune reconstitution inflammatory syndrome (IRIS)?
a)
Pneumocystis jirovecii pneumonia
b)
Tuberculosis
c)
Bacterial pneumonia
d)
CMV retinitis
e)
Oropharyngeal candidiasis
157.
Which factor MOST influences the choice of latent TB treatment regimen in patients with HIV?
a)
CD4 count
b)
HIV viral load
c)
ART–rifampicin drug interactions
d)
Prior BCG vaccination
e)
Duration of HIV infection
158.
Which opportunistic infection is prevented by co-trimoxazole prophylaxis, in addition to Pneumocystis jirovecii?
a)
Cryptococcus
b)
CMV
c)
Mycobacterium avium complex
d)
Toxoplasmosis
e)
TB
159.
Which condition can occur at any CD4 count in people living with HIV?
a)
Cerebral toxoplasmosis
b)
CMV retinitis
c)
Pneumocystis pneumonia
d)
Cryptococcal meningitis
e)
Kaposi sarcoma
160.
Which opportunistic infection has no effective antimicrobial therapy and carries a high risk of long-term neurological disability?
a)
CMV encephalitis
b)
Toxoplasmosis
c)
TB meningitis
d)
Cryptococcal meningitis
e)
Progressive multifocal leukoencephalopathy
161.
Which concept best explains why health care choices must be made between competing interventions?
a)
Marginal utility
b)
Scarcity
c)
Opportunity cost
d)
Equity
e)
Market failure
162.
In a publicly funded system like the NHS, the main role of health economics is to:
a)
Reduce overall health care spending
b)
Improve clinical effectiveness
c)
Maximise population health within a fixed budget
d)
Eliminate health inequalities
e)
Ensure all treatments are funded
163.
Economic evaluation is best defined as:
a)
Choosing the cheapest intervention
b)
Measuring costs alone
c)
Comparing alternatives in terms of costs and consequences
d)
Budget impact analysis
e)
Cost containment strategy
164.
A new intervention has lower cost and better outcomes than the current standard. On the cost-effectiveness plane, this lies in which quadrant?
a)
North-east
b)
North-west
c)
South-west
d)
South-east
e)
Origin
165.
Which economic evaluation method assumes equal health outcomes between interventions?
a)
Cost-effectiveness analysis
b)
Cost-utility analysis
c)
Cost-benefit analysis
d)
Cost-minimisation analysis
e)
Budget impact analysis
166.
Which outcome measure allows comparison across interventions with different clinical effects?
a)
Life-years gained
b)
Number of cases detected
c)
Episode-free days
d)
QALYs
e)
Mortality rate
167.
A patient lives 2 years with a health-related quality of life of 0.5. How many QALYs does this represent?
a)
0.5
b)
1
c)
1.5
d)
2
e)
2.5
168.
The incremental cost-effectiveness ratio (ICER) represents:
a)
Total cost of a new intervention
b)
Difference in outcomes only
c)
Extra cost per additional unit of outcome
d)
Maximum acceptable cost
e)
Budget impact over time
169.
An intervention with an ICER below the NICE threshold is considered:
a)
Clinically superior
b)
Cheaper
c)
Cost-effective
d)
Cost-saving
e)
Dominant
170.
Which economic evaluation expresses outcomes in monetary terms?
a)
Cost-utility analysis
b)
Cost-effectiveness analysis
c)
Cost-minimisation analysis
d)
Cost-benefit analysis
e)
Cost-consequence analysis
171.
A health economic evaluation adopts a societal perspective. Which cost should be included?
a)
Informal carer time
b)
NHS staff salaries only
c)
Drug acquisition costs only
d)
Hospital capital depreciation only
e)
Direct medical costs only
172.
Why is cost-minimisation analysis rarely appropriate in prospective economic evaluations?
a)
Costs are difficult to measure
b)
Outcomes cannot be assumed equal
c)
It ignores indirect costs
d)
It requires QALY measurement
e)
It overestimates efficiency
173.
A new intervention lies in the north-west quadrant of the cost-effectiveness plane. Which statement is correct?
a)
The new intervention should always be adopted
b)
The decision depends on the ICER
c)
The old intervention dominates
d)
The new intervention dominates
e)
The interventions are equivalent
174.
Which feature most clearly distinguishes cost-utility analysis from cost-effectiveness analysis?
a)
Inclusion of indirect costs
b)
Use of natural units
c)
Monetisation of outcomes
d)
Ability to compare across disease areas
e)
Requirement for a comparator
175.
Which scenario most clearly illustrates opportunity cost in health care?
a)
A hospital overspends its annual budget
b)
A cheaper drug is chosen over an expensive one
c)
Funding a cancer drug means fewer hip replacements
d)
A treatment improves survival but worsens QoL
e)
A new service duplicates an existing one
176.
A new intervention increases survival but reduces quality of life. Which method best captures this trade-off?
a)
Cost-effectiveness analysis
b)
Cost-benefit analysis
c)
Cost-minimisation analysis
d)
Budget impact analysis
e)
Cost-utility analysis
177.
An ICER of £18,000 per QALY is calculated for a new drug. What does this imply?
a)
The drug is clinically effective
b)
The drug saves money
c)
The drug should always be adopted
d)
The drug is below NICE's usual threshold
e)
The drug dominates existing care
178.
Which outcome is least appropriate for a cost-effectiveness analysis of antihypertensive therapy?
a)
Reduction in systolic blood pressure
b)
Stroke events prevented
c)
Myocardial infarctions avoided
d)
Quality-adjusted life years
e)
Life-years gained
179.
Which criticism most commonly applies to cost-benefit analysis in health care?
a)
Inability to compare interventions
b)
Exclusion of non-health outcomes
c)
Ethical and methodological difficulty of valuing health in money
d)
Failure to consider opportunity cost
e)
Lack of relevance outside transport economics
180.
Why is a time horizon critical in economic evaluation?
a)
It determines the analytic perspective
b)
It ensures only direct costs are counted
c)
It reflects the discount rate used
d)
It defines whether ICERs are calculated
e)
It ensures all relevant costs and outcomes are captured
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