A 22 year old man with a painful rash

A 22 year old plumber attends the drop-in clinic in the dermatology department at Queen Elizabeth Central Hospital, Blantyre.  He has a 1 day history of a painful vesicular rash on his right buttock and posterior thigh. He feels unwell with fever.

Right posterior thigh

  1. What is your diagnosis?
  2. What is your management?

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This is herpes zoster infection also known as “shingles”.  Varicella zoster virus (VZV) lies dormant in the posterior root ganglion after chicken pox.  Reactivation causes the virus to travel down the cutaneous nerves to infect epidermal cells in the skin.    The presence of pain and the dermatomal distribution is classical.  As the rash is less than 72 hours old it is worthwhile treating with antiviral medication such as aciclovir, famciclovir or valaciclovir, if available.  They inhibit VZV replication and reduce the severity and duration of the rash.  Postherpetic neuralgia (pain which persists >3months after the rash has resolved) is more common in elderly patients and may respond to tricyclic antidepressant drugs, which should be started early if possible.

He is treated with aciclovir 800mg 5 times daily for 7 days and regular paracetemol.

In a young man in an HIV prevalent region, underlying HIV should be suspected (Herpes zoster is categorised by the World Health Organisation as clinical stage 2 of HIV infection) and an HIV test performed.

His HIV test was positive.  His CD4 count should be checked and if ≤350 cells/mm3 antiretroviral therapy commenced.

Further info

This case contributed by Levie Mwale and Ann Sergeant