parakeratosis psoriasiformis
pityriasis lichenoides chronica
An uncommon, idiopathic dermatosis that primarily affects younger patients (under age 30), which is characterised by waves of erythematous, scaly papules that may persist for months.Aetiology
Unknown; thought to be a hypersensitivity reaction to viruses—e.g., EBV, adenovirus, parvovirus B19.
Management
Various modalities have been tried, including phototherapy (UV, solar), topical steroids and antibiotics.