A Rare Case of COVID-19-Induced Acute Exacerbation of Oral Dermatitis Herpetiformis in a Geriatric Patient.

Introduction: Dermatitis herpetiformis (DH) is an autoimmune vesiculobullous disease associated with celiac enteropathy. The clinical manifestation of DH is the occurrence of a papulovesicular rash on the skin. Oral mucosal involvement in DH is very rare. This study aimed to describe the impact of COVID-19 on the acute exacerbation of oral dermatitis herpetiformis.

Case Report: A 74-year-old woman was referred to the Oral Medicine Department with a chief complaint of the blisters on the skin for a week and ulcers in the oral cavity appeared two days ago. Extraoral examination revealed crusts on the neck and extremities. The lips appeared dry and desquamative. Intraoral examination revealed erosive lesions covered with a white-yellowish plaques on the right and left sides of the buccal mucosa, an ulcer with a diameter of 0.5 cm, and purpura hemorrhagic on left buccal mucosa and right lateral border of the tongue. Histopathological examination of the skin lesion revealed a subepithelial blister with eosinophils and neutrophil cells. The definitive diagnosis of dermatitis herpetiformis was made. She was given 5 mg intravenous dexamethasone, cetirizine 10 mg, and clindamycin 300 mg by the dermatologist. We gave hyaluronic acid 0.025% mouthwash for oral ulcers and petroleum jelly for the lips. The oral lesions had significant improvement after 4 weeks of treatment. Two months later, the patient experienced acute exacerbation after being infected with COVID-19 (anti-SARS-CoV-2 IgG S-RBD >40,000 AU/mL). The oral lesions healed after a month of treatment.

Conclusion: COVID-19 can trigger the acute exacerbation of dermatitis herpetiformis. SARS-CoV-2 causes an immune dysregulation and hypersensitivity reaction.