Multiple nonmelanoma skin cancers in a patient with epidermolytic hyperkeratosis on long-standing retinoid therapy.

Epidermolytic hyperkeratosis is a rare genetic disorder of keratinization. In childhood, patients are erythrodermic and have a compromised stratum corneum, replaced with generalized hyperkeratosis as the patients age. Treatment consists of topical emollients as well as, topical and oral retinoids. Ultraviolet (UV) light, often in combination with psoralen ultraviolet A (PUVA) is widely used as a therapeutic modality for a multitude of hyperproliferative disorders. Although not strictly indicated for epidermolytic hyperkeratosis, it has been utilized as experimental treatment, particularly in the days prior to retinoids. Psoralen ultraviolet A has also been implicated in the development of nonmelanoma skin cancers, especially, squamous cell carcinoma (SCC). Retinoids are well-known to protect against nonmelanoma skin. A patient with epidermolytic hyperkeratosis with multiple nonmelanoma skin cancers, previously treated with PUVA and long-standing oral retinoids is reported.