L-tryptophan ingestion associated with eosinophilic fasciitis but not progressive systemic sclerosis

To assess the use of L-tryptophan by patients with eosinophilic fasciitis and compare this with its use by patients with progressive systemic sclerosis (scleroderma).

Retrospective and prospective analysis. Six patients with eosinophilic fasciitis were identified retrospectively and two prospectively. Retrospective identification of patients was done by questioning hospital-affiliated rheumatologists and dermatologists and by searching the hospital dermatopathology database. The patients with scleroderma or morphea were prospectively identified by questioning consecutive office patients with these established diagnoses.

University of Pennsylvania rheumatology and dermatology practices.

Eight patients with eosinophilic fasciitis; 40 consecutive patients with scleroderma (27 with diffuse cutaneous and 13, limited cutaneous disease); 3 patients with morphea.

All eight patients with eosinophilic fasciitis had taken L-tryptophan before the onset of their disease. All had myalgias and high peripheral eosinophil counts (most greater than 5000 cells/mm3). Only 1 of 40 patients with scleroderma (no patients with morphea) had used L-tryptophan preceding illness (P less than 0.001 compared with eosinophilic fasciitis). Six patients with eosinophilic fasciitis had taken L-tryptophan for less than 8 months. One patient had taken it for 9 years before developing skin induration. Two patients were newly identified as having hypothyroidism; two developed neuropathy; and two had severe flexion contractures (several occurring in areas without skin induration). Five patients had low-titer antinuclear antibodies, indicating a possible autoimmune process. Most patients had only a partial response to systemic corticosteroid therapy. One patient has had important disease regression in response to isotretenoin therapy that was evident even while she continued to take L-tryptophan.

L-Tryptophan use can lead to eosinophilic fasciitis whereas it does not appear to cause classic scleroderma. The disease process does not automatically remit after discontinuation of L-tryptophan-containing products.