Primary Varicella in an Adult Patient With Diabetes.

Although the introduction of the varicella vaccine has significantly reduced the incidence of primary varicella in adults, individuals with compromised immune systems, such as those with diabetes mellitus, remain at heightened risk for severe disease. We report the case of a 44-year-old male with a history of diabetes mellitus who presented to the emergency department with a diffuse, generalized rash associated with pruritus, burning sensation, and numbness and tingling. A polymorphic rash diffusely involving the face, trunk, extremities, scalp and palms emerged, beginning with erythematous macules and sequentially developing into papules, vesicles, and crusted lesions. A clinical diagnosis of primary varicella was made based on the characteristic rash and the patient's immunocompromised status, which was confirmed with antibody testing. He was treated with valacyclovir, corticosteroids, multimodal pain control, and antihistamines. This case highlights the continued risk of primary varicella in adults and the importance of considering it within the differential diagnosis, particularly in patients with immune dysfunction.