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Photosensitivity Ampiroxicam Piroxicam Photopatch test Minoru Chishiki, MD, Department of Dermatology, National Defense Medical College, Namiki 3-2, Tokorozawa City, Saitama 359 (Japan), Tel. +81 429 95 1665, Fax +81 429 96 5209 Piroxicam is known to induce photosensitivity. Ampiroxicam has been developed as an ethoxycarbonyl ether prodrug of piroxicam. We describe here a case with photosensitivity due to ampiroxicam. An 84-year-old woman was seen in July 1996 with pruritic and well-delineated erythema and papules on sun-exposed areas that had started 4 days before. She had no history of photosensitivity. She had started taking ampiroxicam (Flucam®, Toyama Chemicals Co. Ltd.. Tokyo, Japan) 13.5 mg b.d.s. orally because of arthritis of both knees 7 days before. There were no abnormal findings on hematological examination, blood chemistry or urinalysis, including porphyrins of peripheral erythrocytes and urine. Histological findings of erythema on the right forearm demonstrated intercellular edema and perivascu-lar lymphohistiocytic dense infiltration. We performed a screening phototest, as described before [1], with a Dermaray Model M-DMR-1 (Eisai Co. Ltd.) as a light source [2, 3] 3 months after she had stopped the drug. The UVB minimal erythema dose for this patient was normal (50 mJ/cm2), and irradiation of 13.5 J/cm2 for UVA elicited no response, suggesting that photosensitivity of the patient had become normal. Patch and photopatch tests were made with ampiroxicam and piroxicam (10, 1 and 0.1% in petrolatum). Ampiroxicam (10 and 1% in petrolatum) and piroxicam (10, 1 and 0.1 % in petrolatum) with UVA irradiation (4.5 J/cm2) on photopatch test showed erythema 1 and 2 days after irradiation. Patch tests with thiosalicylic acid (1 and 0.1 % in petrolatum) and thimerosal (0.05% in petrolatum) were positive 2 days after application, while a patch test with mercuric chloride (0.05%) was negative. Patch and photopatch tests with ampiroxicam and piroxicam in 6 normal subjects showed no response 2 days after application or 1 day after irradiation. Ampiroxicam, a prodrug of piroxicam, has been in use since 1994 as a nonsteroidal antiinflammatory drug. Inactive ampiroxicam is hydrolyzed to active piroxicam by an intestinal carboxyesterase during absorption through the intestinal wall [4]. Our case and 2 reported cases