A 2-day-old, full-term male infant develops a rash consisting of firm, yellow-white 1- to 2-mm papules and pustules, each surrounded by a distinct erythematous flare. The lesions are scattered over his trunk and limbs, but the palms and soles are spared. A Wright-stained smear of a pustule’s contents reveals numerous eosinophils. What is the most likely diagnosis?
A 6-year-old boy presents with patches of alopecia and scaling on his scalp. Examination reveals numerous hairs broken off close to the follicle, creating a “black-dot” appearance. Wood lamp examination of the scalp is negative. What is the most likely causative organism for this tinea capitis presentation?
A 14-year-old girl presents with a linear, indurated, sclerotic, and atrophic plaque extending from her scalp down her forehead. This “en coup de sabre” presentation of morphea carries a poorer prognosis due to its strong association with which of the following?
A 16-year-old boy presents with a widespread eruption of small, oval, pink papules with a fine, crinkly scale, primarily on his trunk. He recalls a single, larger, annular patch appearing on his chest about 10 days earlier. The long axis of the lesions appears to align with cutaneous cleavage lines, creating a “Christmas tree” pattern on his back. What is the most appropriate management for this condition?
A 3-week-old neonate, brought in for a well-child check during a heatwave, is found to have an eruption of asymptomatic, noninflammatory, pinpoint, clear vesicles over his trunk. The provider notes these vesicles are due to sweat retention from immature sweat ducts. What is the most likely diagnosis?
A 7-year-old girl presents with a solitary, firm, 1 cm, deep dermal nodule on her cheek. The overlying skin has a bluish-red tint, and the lesion feels hard on palpation. Histopathology reveals islands of epithelial cells with anucleate “ghost cells” and calcium deposits. This benign tumor, pilomatricoma, is associated with pathogenic variants in which gene?
An 8-year-old girl with no significant family history presents with slowly progressive fat loss affecting her face, neck, and upper trunk in a cranial-to-caudal distribution. On examination, there is an accumulation of fat in her hips, buttocks, and legs. This patient is at highest risk for developing which of the following associated autoimmune diseases?
A 15-year-old female presents with multiple tender, symmetric, bright red nodules on her shins that appeared one week ago. She reports having had a sore throat two weeks prior, and a rapid streptococcal test was positive. The nodules are painful but have not ulcerated. What is the most likely diagnosis?
A 7-year-old girl is brought in for a new, rapidly growing pink papule on her cheek that appeared over the last few months. The lesion is a 6-mm, symmetric, dome-shaped, firm papule. A biopsy reveals a proliferation of spindle and epithelioid melanocytes. What is the most likely diagnosis?
A 5-year-old boy with a history of recurrent ear infections is treated with a cephalosporin. Ten days later, he develops a fever of 38.5°C (101.3°F), arthralgias, and a widespread rash consisting of annular, urticarial plaques with a dusky, lavender-colored center. Laboratory evaluation is notable for the absence of circulating immune complexes and renal involvement. What is the most likely diagnosis?
