Anastrozole-Induced Subacute Cutaneous Lupus Erythematosus
Drug-induced subacute cutaneous lupus erythematosus (DI-SCLE) has been associated with numerous drugs, but there are limited reports of its association with aromatase inhibitor anastrozole. We report the case of a patient undergoing treatment with anastrozole for breast cancer who presented with clinical, serological, and histological evidence consistent with DI-SCLE. Her condition quickly began to improve after the use of anastrozole was discontinued and hydroxychloroquine therapy was initiated. Cases such as ours as well as several others that implicate antiestrogen drugs in association with DI-SCLE seem to be contradictory to studies looking at the usefulness of treating systemic lupus erythematosus (SLE) with antiestrogen therapy. Further research on this relationship is warranted.
Practice Points
- There are numerous cases of drug-induced subacute cutaneous lupus erythematosus (DI-SCLE) published in the literature; however, there are limited reports with anastrozole implicated as the causative agent.
- Cases of DI-SCLE are clinically and histologically indistinguishable from idiopathic cases. It is important to recognize and withdraw the offending agent.
Case Report
A 69-year-old woman diagnosed with breast cancer 4 years prior to her presentation to dermatology initially underwent a lumpectomy and radiation treatment. She was subsequently started on anastrozole 2 years later. After 16 months of treatment with anastrozole, she developed an erythematous scaly rash on sun-exposed areas of the skin. The patient was seen by an outside dermatologist who treated her for a patient-perceived drug rash based on biopsy results that simply demonstrated interface dermatitis. She was treated with both topical and oral steroids with little improvement and therefore presented to our office approximately 6 months after starting treatment seeking a second opinion.
Physical examination revealed numerous erythematous scaly papules and plaques in a photodistributed pattern on the chest, back, legs, and arms (Figure 1). On further questioning, the patient noted that the rash became worse when she was at the beach or playing tennis outside as well as under indoor lights. A repeat biopsy was performed, revealing interface and perivascular dermatitis with an infiltrate composed of lymphocytes, histiocytes, and scattered pigment-laden macrophages (Figure 2). Given the appearance and distribution of the rash as well as the clinical scenario, drug-induced lupus was suspected. Anastrozole was the only medication being taken. Laboratory evaluation was performed and was negative for antinuclear antibodies, antihistone antibodies, and anti-La/SS-B antibodies but was positive for anti-Ro/SS-A antibodies (>8.0 U [reference range, <1.0 U]). Based on these findings, anastrozole-induced SCLE was the most likely explanation for this presentation. The patient was started on a sun-protective regimen (ie, wide-brimmed hat, daily sunscreen) and anastrozole was discontinued by her oncologist; the combination led to moderate improvement in symptoms. One week later, oral hydroxychloroquine 200 mg twice daily was started, which led to notable improvement (Figure 3). The patient was seen for 2 additional follow-up visits, each time with sustained resolution of the rash. The hydroxychloroquine was then stopped at her last visit 3 months after diagnosis. The patient was subsequently lost to follow-up.
