Reactive perforating collagenosis in Adult
There is also a familial form of RPC, which has an onset in childhood. Familial RPC can persist throughout childhood and into adulthood, and generally presents on the hands and upper extremities. Lesions are induced by trauma.
The pathogenesis is unknown, but the familial disease is generally thought to be inherited in an autosomal recessive manner (although an autosomal dominant pattern has been observed in some families). Males and females are equally affected, and lesions generally start within the first few years of life in the inherited form.
The primary lesion is a skin-colored papule 1-3 mm in diameter that reaches a maximum size of about 6 mm within a month; 6-8 weeks later, it regresses spontaneously (often leaving temporary areas of hypopigmentation behind or slight scarring). There is a central keratotic plug seen in more advanced lesions that is firmly adherent and, if removed, results in bleeding. Koebner phenomenon may occur, resulting in new lesions that are often linearly arranged. Pruritus is often severe. There are often periods of disease remission and exacerbation.
L87.1 – Reactive perforating collagenosis
64036004 – Reactive perforating collagenosis
Differential Diagnosis & Pitfalls
- Elastosis perforans serpiginosa – Lesions often occur in young adults rather than young children; they are also often annular or serpiginous and do not exhibit Koebner phenomenon. The lesions generally only affect one anatomic area.
- Perforating folliculitis – Papules are generally asymptomatic, whereas lesions of reactive perforating collagenosis are very pruritic. The keratotic plug is generally white and often contains a curled-up hair in the center, in contrast to the dark brown or blacker keratotic plugs of reactive perforating collagenosis.
- Kyrle disease – Lesions usually occur in adults (although rarely in children); they are commonly bilateral and favor the lower extremities. The individual papules are generally reddish and often coalesce into plaques.
- Arthropod bites
- Papular urticaria
- Molluscum contagiosum
- Excoriations from various causes
- Prurigo nodularis
- Perforating of exogenous foreign material
- Perforating of endogenous foreign material
- Multiple keratoacanthomas
Drug Reaction Data