Carbamazepine‐induced eruption historically mimicking mycosis fungoides

Abstract

Carbamazepine is an important drug used in the management of seizures, trigeminal neuralgia, and chronic pain syndromes. It has been associated with a variety of adverse skin reactions including urticaria, lichenoid eruptions, erythroderma, erythema multiforme, Stevens-Johnson syndrome, and toxic epidermal necrolysis. A 39-year-old white male had been started on carbamazepine for intractable pain which resulted from a right foot crush injury. Approximately 3 months after the start of therapy, the patient had developed a generalized skin eruption following an entire day of sun exposure. Skin biopsies revealed an atypical lymphoid infiltrate in the dermis with collections of the atypical lymphocytes within spongiotic vesicles in the epidermis, suggestive of mycosis fungoides. The patient was treated with systemic prednisone. Subsequent biopsies failed to reveal atypical lymphocytes. Previous reports have described spongiotic eruptions with foci of atypical lymphocytes in contact dermatitis and in patients treated with phenytoin. To the best of our knowledge, this is the first reported case of a carbamazepine-induced eruption simulating mycosis fungoides histologically.

Patch testing in cutaneous reactions caused by carbamazepine

“…The laboratory findings may include an abnormality in liver function tests (GOT, GPT) and an increase in the number of eosinophilic granulocytes or an appearance of reactive lymphocytes in the peripheral blood. This syndrome has been described as "serum-sickness-like reaction" (10,11) and "pseudolymphoma syndrome" (11,12). Carbamazepine can also cause fixed drug eruptions and erythema multiforme reactions as well as exfoliative dermatitis (erythrodermas).…”

Lichenoid dermatitis from immune checkpoint inhibitor therapy: An immune‐related adverse event with mycosis‐fungoides‐like morphologic and molecular features

“…Lichenoid drug reactions may mimic MF, and medications associated with this histologic reaction pattern include carbamazepine, penicillin, β‐blockers, and angiotensin‐converting enzyme inhibitors, among others . More recently, therapy with monoclonal antibodies, such as efalizumab, for treatment of psoriasis was associated histologically with an MF‐like lichenoid reaction .…”

Controversies and Considerations in the Diagnosis of Primary Cutaneous CD4+ Small/Medium T-Cell Lymphoma

“…13,14,20,[33][34][35] The underlying cause of most cases of T-cell-rich pseudolymphomas is idiopathic. 11,14,34 Common known causes include lymphomatoid drug reaction, 14,34,[36][37][38][39][40][41] lymphomatoid contact dermatitis, 14,33,[42][43][44][45] and persistent, nodular, arthropod-bite reaction, 14,33 among others. Morphologically, reactive lymphoid infiltrates in the skin (pseudolymphomas) may display a marked similarity to PC-SMTCL.…”