Ultrasound imaging of fasciitis due to body-building supplement.

Background: Fascia and soft tissues, rich in collagen, receptors of pain and capable of significant distention, may be targets of autoimmune inflammatory diseases. We observed fasciitis due to the protein supplement Pure Whey, which has not been reported previously.
Methods: Sonography (Sonosite-Titan, 5 to 10 MHz, L-38) was performed on a patient (age, 26 years; body mass index, 38 kg/m2) with protein fasciitis. He had developed compact swelling of his forearms, hands, and legs, with skin irregularity and severe disability (without peripheral eosinophilia, normal Ig and ESR 18/hr) after taking Pure Whey, containing L-tryptophan (1.4 g per 100 g of protein). A deep skin biopsy was performed. The thickness of the brachioradial fascia (BRF) was measured and compared with 10 healthy control subjects (men ages 36.7 +/- 8.3 years; body mass index, 26.4 +/- 6.5 kg/m2).
Results: The deep skin biopsy showed severe fat interlobular and fascial thickening with mononuclear (noneosinophilic) infiltrate and fibrosis associated with fasciitis. BRF of the 10 healthy men had a thickness of 0.75 +/- 0.19 mm, compared with the patient's 2.4 mm thickened and cleaved BRF. After 2.5 months of corticosteroid therapy (30 mg/d with tapering) and discontinuation of the protein supplement, the patient's BRF returned to a monolayer appearance. Its thickness reduced to normal (0.8 mm), with significant clinical improvement.
Conclusions: This case of noneosinophilic fasciitis associated with ingestion of L-tryptophan-containing protein supplement responded favorably to corticosteroid therapy. Sonography proved to be an effective method to visualize and confirm the fasciitis and to follow the course and therapy.