A 34 Y/O F, a landscaper, c/o an intensely pruritic, erythematous, vesicular rash on her forearms and hands x3D. She reports working in a wooded area 2 days prior to rash onset. O/E, there are linear streaks of erythematous papules and vesicles on a swollen, red base over the dorsal aspects of both hands and forearms. Some vesicles are weeping clear fluid. Vitals: stable. What is the most appropriate initial management for this patient's condition?

A 45 Y/O M presents with a 2-week Hx of cough, SOB, and hemoptysis. He also reports recurrent sinusitis. O/E: BP 150/95, HR 105, RR 22, T 38.1°C. Ix: Serum creatinine is 3.2 mg/dL (was 0.9 mg/dL 6 months ago). Urinalysis shows dysmorphic RBCs and red cell casts. A CXR reveals multiple bilateral nodules, some with cavitation. A renal biopsy confirms pauci-immune, focal necrotizing glomerulonephritis. Which of the following serological markers is most specifically associated with this patient's most likely diagnosis?

A 34 Y/O F with a known Hx of SLE (on hydroxychloroquine and low-dose prednisone) presents to the ED with a 24-hour Hx of acute confusion, headache, and a new-onset focal seizure. O/E: T=38.1°C, BP=150/95 mmHg, HR=105/min. She is disoriented to time and place with R-sided hemiparesis (3/5 power). Initial Ix show: ↓C3/C4, ↑anti-dsDNA titers. An urgent MRI brain reveals multiple, bilateral, small ischemic infarcts in different vascular territories. What is the most definitive Ix to establish the diagnosis?

A 34 Y/O F with a known Dx of SLE presents with a 4-week Hx of progressive muscle weakness. She reports significant difficulty getting up from a chair and combing her hair. She is currently on hydroxychloroquine for cutaneous and joint symptoms. O/E: Vital signs are stable. Proximal muscle power is 3/5 in the upper and lower extremities. Ix: Creatine Kinase (CK) is significantly elevated at 3500 U/L (N: 22-198). Urinalysis is bland. What is the most appropriate initial management for her current condition?

A 34 Y/O M presents with a 3-month Hx of pruritic, erythematous plaques with a silvery scale on his extensor elbows, lower back, and in the R) axilla. Total body surface area (BSA) affected is ~10%. O/E, well-demarcated plaques are noted. Linear plaques are seen along a recent scratch mark on his forearm (Koebner phenomenon). The clinical Dx is plaque psoriasis, but the patient requests a confirmatory test. A skin biopsy is performed. Which of the following histopathological findings is most specific for psoriasis?

An 8 Y/O F is brought to the clinic c/o severe pain in her R knee that started yesterday. Today, the R knee feels better, but she now has significant pain and swelling in her L ankle. Hx reveals a sore throat approx. 3 weeks ago, which resolved without Rx. O/E, T=38.4°C, HR=110 bpm, BP=100/65 mmHg. Her L ankle is erythematous, warm, and tender. Her R knee shows minimal tenderness. Cardiac auscultation reveals a new holosystolic murmur at the apex radiating to the axilla. ECG shows a prolonged PR interval. Which of the following investigations is most crucial to support the suspected diagnosis?

A 35 Y/O M from a TB-endemic region presents with a 4-month Hx of progressively worsening R knee pain and swelling. The onset was insidious with no Hx of trauma. He reports occasional night sweats but no cough. O/E: BP 120/80, HR 88, T 37.5°C. There is a moderate effusion in the R knee with diffuse tenderness and restricted ROM. The joint is not erythematous or markedly warm. Ix: WBC 9.5x10⁹/L, ESR 60 mm/hr. X-ray of the knee reveals periarticular demineralization and subtle marginal bone erosions. What is the most likely Dx?

A 10 Y/O F is brought to the clinic c/o progressive muscle weakness over 3 months, making it difficult to climb stairs & comb her hair. Hx reveals a purplish rash over her eyelids & red, scaly papules on her knuckles. O/E: Symmetrical proximal muscle weakness (4/5 power). Violaceous discoloration of the eyelids (heliotrope rash) & erythematous papules over the metacarpophalangeal joints (Gottron's papules) are noted. Ix: ↑ CK, ↑ aldolase, & positive anti-Jo-1 antibodies. An X-ray of the thighs reveals subcutaneous sheet-like calcifications. What is the most likely diagnosis?

A 25 Y/O F presents to the ED with a 1-week Hx of persistent headaches and recent personality changes, including irritability and confusion. Her partner notes she took aspirin for her headache last week with no relief. O/E, she is afebrile with normal vital signs. There is a prominent erythematous, macular rash over her cheeks and the bridge of her nose. Neurological examination is significant for mild cognitive slowing but no focal deficits.