Anything Rare is Possible: Letrozole Induced Eczematous Skin Eruption

Area of Science:

• Oncology
• Dermatology
• Pharmacology

Background:

• Letrozole is a widely used first-line endocrine therapy for hormone-sensitive breast cancer in postmenopausal women.
• It generally exhibits a favorable tolerability profile with rare significant adverse reactions.
• Early-stage and advanced breast cancer patients commonly receive letrozole treatment.

Observation:

• A 61-year-old female diagnosed with invasive ductal breast carcinoma developed an eczematous skin eruption.
• The eruption, characterized as moderate to severe drug eruption, appeared six weeks after initiating daily letrozole therapy.
• Skin lesions recurred rapidly upon rechallenge with letrozole, confirming the drug's role.

Findings:

• This case represents the first reported instance of an eczematous drug eruption associated with letrozole treatment.
• The adverse reaction was clearly linked to letrozole, as evidenced by the recurrence upon rechallenge.
• The patient experienced generalized, itchy skin lesions attributed to the medication.

Implications:

• Clinicians should be vigilant for potential dermatological adverse reactions, such as eczematous eruptions, during letrozole therapy.
• This report highlights the importance of considering drug-induced reactions in patients presenting with new-onset skin lesions while on letrozole.
• Further pharmacovigilance may be warranted to fully understand the incidence and spectrum of letrozole-induced skin reactions.