Occasionally, lesions may be eczematous, urticarial, bullous, ulcerative, or nodular. Burning or itching also may occur. Lesions may be localized to any area of the body, including the buccal or genital mucosa. Diagnosis and Treatment A search for the underlying cause of the eruption should be made. If lesions occur at the same site each time a specific drug is administered, the diagnosis of a fixed drug eruption caused by that specific agent is confirmed.
Treatment consists of application of a topical steroid and avoidance of the drug.
It is thought to be an allergic reaction pattern of delayed hypersensitivity to both infectious and noninfectious agents. The eruption may be preceded by fatigue, arthralgia, weight loss, or malaise. Fever usually accompanies the eruption. The nodules may acquire a violaceous hue similar to that of a bruise. Lesions usually resolve in three to six weeks.