Immunotherapy and concomitant antibiotic treatment: A cautionary case report of a potential oral adverse event

Erythematous oral lesions have a broad differential diagnosis, including trauma, vascular lesions, precancer and cancer, and opportunistic infections. The authors present a case of erythematous palatal lesions in a male patient undergoing concurrent immunotherapy and antibiotic therapy.

A 38-year-old man with ankylosing spondylitis undergoing long-term adalimumab (Humira; AbbVie) therapy sought treatment for asymptomatic erythematous palatal lesions after amoxicillin use. Clinical examination revealed multiple well-defined flat red lesions involving the hard and soft palate. Although the manifestation was atypical, a clinical diagnosis of erythematous candidiasis was made. Nystatin mouthrinse was prescribed and resulted in complete resolution of the lesions, supporting the clinical diagnosis. No recurrence was observed at 6-month follow-up.

With immunotherapy use becoming more common, dental care professionals should recognize the increased risk of developing opportunistic infections that may manifest atypically in these patients. A thorough medical history is essential.