This summary discusses psoriasis in infants. Psoriasis in adults and children is addressed separately.

Psoriasis is a chronic inflammatory skin disease that is seen in less than 1% of infants by 1 year of age and 2% of infants by age 2. Infantile psoriasis resembles adult psoriasis with discrete oval, erythematous plaques with white scale often involving the trunk, extremities, and face. There is usually less white scale on the plaques of infants as compared to adults. Lesions may be pruritic. The disease process results in hyperproliferation of epidermal cells causing thickened, often scaly skin. Lesions usually develop slowly but may have a sudden onset. Psoriasis in infancy typically involves the diaper area and face. Nail findings of pitting, onycholysis, oil spots, and subungual hyperkeratosis are present in 10% of affected infants.