Herpes Zoster Without Vesicles: An Atypical Linear Erythematous Plaque on the Inner Thigh.

Herpes zoster (HZ), caused by the reactivation of the varicella-zoster virus (VZV), typically presents with a painful, vesicular rash along a dermatomal distribution. This case reports an unusual presentation in a 44-year-old female with hypothyroidism and urticaria, who presented with a solitary, linear erythematous plaque on the inner thigh, associated with burning pain. Initial topical treatments were ineffective, but prompt antiviral therapy with acyclovir led to complete resolution within six weeks. The case highlights the diagnostic challenges posed by atypical presentations of HZ and the importance of early diagnosis and treatment to prevent complications, such as postherpetic neuralgia. It also emphasizes the need to consider HZ in differential diagnoses even in the absence of typical vesicular eruptions to facilitate timely intervention and improved patient outcomes.