A 40-year-old woman presented with fatigue and labial crusts, ulcerations, blister remnants, and multiple painful ulcerations in the floor of her mouth, tongue, buccal mucosa, and soft palate, all on a background of an erythematous mucosa for 1 week (Figure 1).

The medical history revealed that the patient had had psoriatic arthritis and psoriais vulgaris for 12 years. She commenced a once-weekly dose of methotrexate 10 mg 6 months earlier. Although she had responded well initially, her psoriatic arthritis had worsened 1 month before admission. Then, by her own decision, she took methotrexate 10 mg daily for about 20 days.

On admission, laboratory studies showed hematocrit 34.9%, white blood cells 1,700/mm3, platelets 168,000/mm3, erythrocyte sedimentation rate (ESR) 45 mm/h, C-reactive protein 20.5 mg/dL, ALT 980 UI/L (N<45), AST 587 UI/L (N<40), GGT 85 UI/L (N<35), and LDH 556 UI/L (N<190).

Initial clinical impression was suggestive for erythema multiforme or Stevens-Johnson syndrome but our patient did not have any other skin finding such as target lesions.

Other mucosal surfaces (genital and ocular) were intact and viral infections were ruled out. So we assumed that methotrexate was the culprit for toxic hepatitis and oral mucositis and thus it was stopped.

Mupirocin ointment for lips, chlorhexidine gluconate, and benzydamine hydrochloride mouthwashes for oral mucosa were started for symptomatic relief. One week later, all blood parameters returned to normal levels and mucosal ulcerations were partially resolved (Figure 2A). At review (after 3 weeks), the patient’s symptoms and ulcerations had resolved almost entirely (Figures 2B, C, D).

Methotrexate is increasingly being used in the management of chronic inflammatory disorders, however practitioners should be mindful of possible liver toxicity and mucosal side effects.

Author information: Nadir Goksugur, Assistant Professor, Department of Dermatology; Fahrettin Yilmaz, Assistant Professor, Department of Otorhinolaryngology; Izzet Baysal Medical Faculty, Izzet Baysal University, Bolu, Turkey

Correspondence: Dr Nadir Goksugur, Abant Izzet Baysal, University Medical Faculty, Department of Dermatology, 14280 Golkoy, Bolu, Turkey. Fax: +90 374 2534615; email: nadirgo@yahoo.com or goksugur_n@ibu.edu.tr