L-tryptophan syndrome: histologic features of scleroderma-like skin changes

The eosinophilia-myalgia syndrome (EMS) associated with the ingestion of L-tryptophan (LT) containing products has recently been recognized in the United States. We report the histologic features of the cutaneous scleroderma-like changes in four patients. All of the patients met the Center for Disease Control criteria for EMS and had a history of LT ingestion. Skin biopsies showed increased dermal mucin and dermal sclerosis, with trapping of adnexal structures. There are clinical and histologic similarities between EMS, scleroderma, the toxic oil syndrome, and fasciitis with eosinophils.