Pityriasis lichenoides

Pityriasis lichenoides

Pityriasis lichenoides is uncommon. It occurs in two forms. The numerous small circular scaly macules and papules of the chronic type are easy to confuse with guttate psoriasis. However, their scaling is distinctive in that single silver-grey scales surmount the lesions (mica scales). The acute type is characterized by papules that become necrotic and leave scars like those of chickenpox. More often than not there are a few lesions of the chronic type in the acute variant and vice versa. UVB radiation can reduce the number of lesions and spontaneous resolution occurs eventually.