[Lichenoid pityriasis (parapsoriasis guttata) in children. Report of 17 cases]

Seventeen cases of pityriasis lichenoides diagnosed over a nine-year period in children under 15 years of age are reported. Patients with this benign disease develop papular skin lesions covered with thick, coherent scales which detach in a single piece (reminiscent of sealing wax). Pruritus is not marked. Lesions may be necrotic (Mucha Habermann's small pox-like form, n = 6) or mild (leukodermic form, n = 2). Half of the patients studied developed several episodes and total duration of the disease exceeded two years in one third of cases. Recovery occurred after one or two episodes in half the children. Scars developed in some patients with severely necrotic lesions. None of the patients developed lymphoma. All patients with lymphomatoid papulosis progressing to lymphoma reported in the literature were adults. Pathogenesis of pityriasis lichenoides remains unknown but may involve lymphocytic vasculitis. No truly effective therapy is available. However, oral macrolides can be used especially in patients with early manifestations suggesting an infectious disease. Emollients, heliotherapy and ultraviolet therapy may also be recommended.