Fluconazole induced herpes labialis-like lesions in an adult male

Abstract

Fluconazole is a bistriazole commonly prescribed for the treatment of various fungal infections caused by yeasts and dermatophytes. However, there have been several reports of rare Adverse Drug Reactions (ADRs) like Fixed Dose Eruption (FDE), Toxic Epidermal Necrolysis and Stevens Johnson Syndrome following oral administration of fluconazole. We report a rare case of fluconazole induced oral mucosal lesions, mimicking herpes labialis, in a 34 year old male patient receiving oral fluconazole for the treatment of allergic fungal sinusitis. Case report A 34 year old man presented with multiple, painless, shallow erosions, measuring about 1 cm in diameter, over the mucosal surface of the upper lip and the outer surface of the lower lip along with burning, itching and crusting. The erosions developed from painful vesicles characteristic of localised herpes simplex. Tzanck test for herpes simplex infection was negative. The patient suffered from perennial allergic rhinosinusitis for one year which was treated with topical steroids, antibiotics and antihistaminics leading to intermittent remission of symptoms. A CT scan of the paranasal sinuses showed opacification of both the maxillary and anterior ethmoid sinuses with diffuse intrasinus area of increased attenuation, suggesting fungal sinusitis. Hence, oral fluconazole 150mg once daily was started presumptively for a week. History revealed that fluconazole treatment was concomitantly associated with the development of herpes labialis-like vesicles. The first episode of blistering started after the intake of the third tablet of fluconazole. There were no other constitutive symptoms. Therefore, a Fixed Dose Eruption (FDE) to fluconazole was suspected. Oral provocation test with fluconazole 150mg was performed in the following week with the patient’s consent. The patient developed burning sensation and erythema on the mucosal aspect of both the lips, developing into herpes-like vesicles at the same site on the very next day and painful erosions by the fourth day, mimicking the earlier episode. (Figure 1)The erosions healed within a week of stopping fluconazole and the patient continued receiving treatment for allergic rhinosinusitis. The ADR was reported to the peripheral pharmacovigilance centre of the state under the National Pharmacovigilance Programme India.