Imatinib Mesylate–Induced Lichenoid Drug Eruption

Imatinib mesylate is a tyrosine kinase inhibitor initially approved by the US Food and Drug Administration in 2001 for chronic myeloid leukemia (CML). The indications for imatinib have expanded since its initial approval. It is increasingly important that dermatologists recognize adverse cutaneous manifestations associated with imatinib and are aware of their management and outcomes to avoid unnecessarily discontinuing a potentially lifesaving medication.

Adverse cutaneous manifestations in response to imatinib are not infrequent, accounting for 7% to 21% of all side effects.¹ The most frequent cutaneous manifestations of imatinib are dry skin, alopecia, facial edema, and photosensitivity rash, respectively.¹ Other less common manifestations include exfoliative dermatitis, nail disorders, psoriasis, folliculitis, hypotrichosis, urticaria, petechiae, Stevens-Johnson syndrome, erythema multiforme, Sweet syndrome, and leukocytoclastic vasculitis.

We report a case of imatinib-induced lichenoid drug eruption (LDE), a rare cutaneous side effect of imatinib use, along with a review of the literature.

Case Report

An 86-year-old man with a history of gastrointestinal stromal tumors (GISTs) and myelodysplastic syndrome presented with diffuse hyperpigmented skin lesions on the trunk, arms, legs, and lower lip of 2 weeks’ duration. He had been taking imatinib 400 mg once daily for 5 months for GIST. Although the oncologist stopped the medication 2 weeks prior, the lesions were persistent and gradually expanded to involve the trunk, arms, legs, and lower lip. He denied any pain or pruritus. Physical examination revealed multiple ill-defined, brown to violaceous, slightly scaly macules and patches on the trunk (Figures 1A and 1B), arms, and legs (Figure 1C), as well as violaceous to erythematous patches on the mucosal aspect of the lower lip (Figure 2). Two 4-mm punch biopsies were performed from the chest and back, which revealed an atrophic epidermis, lichenoid infiltration, and multiple melanophages in the upper dermis consistent with LDE (Figure 3). Direct immunofluorescence was negative. Therefore, based on the clinicopathologic correlation, the diagnosis of imatinib-induced LDE was made. He was treated with clobetasol ointment twice daily for 3 weeks with some improvement. His GIST was stable on follow-up computed tomography 3 months after presentation, and imatinib was resumed 1 month later with continued rash that was stable with topical corticosteroid treatment.

Figure 1. Widespread violaceous, hyperpigmented, slightly scaly macules and patches on the chest (A), back (B), and leg (C).

Figure 2. Lacy, violaceous to erythematous patches on the mucosal surface of the lower lip.

Figure 3. Atrophic epidermis, lichenoid infiltration of lymphocytes, and multiple melanophages in the upper dermis on histopathology (A and B)(H&E, original magnifications ×40 and ×100).