A 22-year-old man with a history of Ehlers-Danlos syndrome presents with multiple small, keratotic papules arranged in an arc on the trunk.
The lesions have been slowly enlarging and are mildly pruritic. A biopsy reveals transepidermal elimination of thickened, abnormal elastic fibers. Which of the following is the most likely diagnosis?
A. Kyrle disease
B. Elastosis perforans serpiginosa
C. Lichen planus
D. Reactive perforating collagenosis
E. Papular elastorrhexis
Rationale:
When approaching a patient with serpiginous or annular keratotic papules, especially in the context of a connective tissue disorder (e.g., Ehlers-Danlos or Marfan syndrome), you should consider perforating dermatoses. Elastosis perforans serpiginosa (EPS) is a perforating dermatosis marked by transepidermal elimination of elastic fibers. It presents with keratotic papules in arcuate or serpiginous patterns, often on the neck, face, or upper extremities. It is associated with multiple conditions including connective tissue disorders (Ehlers-Danlos, Marfan, osteogenesis imperfecta) and Penicillamine therapy. Histopathology shows abnormal elastic fibers within the dermis protruding through a cup-shaped epidermal depression.
Correct Answer:
B. Elastosis perforans serpiginosa
Incorrect answer choices:
A. Kyrle disease typically occurs in patients with renal failure or diabetes, presenting as large keratotic papules with a central keratotic plug. Histology shows degenerative debris eliminated through the epidermis, not abnormal elastic fibers.
C. Lichen planus classically presents as violaceous, flat-topped, polygonal papules, commonly on the wrists and legs. It does not display transepidermal elimination or the characteristic histologic findings of EPS.
D. Reactive perforating collagenosis involves transepidermal elimination of collagen, not elastic fibers, and usually follows trauma. It often presents with umbilicated papules and may be associated with diabetes or renal disease.
E. Papular elastorrhexis is a rare condition presenting with hypopigmented, non-follicular papules on the trunk and upper arms, typically in children or adolescents. Histology shows fragmentation of elastic fibers, but no transepidermal elimination.
Additional reading at Fitzpatrick's Dermatology Chapter 71: Acquired Perforating Disorders