Varicella zoster virus (VZV) may result in cutaneous disease in primary infection as well as secondary reactivation in the context of immune latency, where it is referred to as herpes zoster (HZ). (27) HZ occurs up to 20-fold more frequently in PLWHIV compared to their seronegative counterparts (28) particularly among men who have sex with men and those with CD4+ counts below 200 cells/μL. (29) Moreover, recurrent HZ is estimated to occur in 27% of patients with advanced HIV, and is significantly reduced by ART. (29) Although mortality from varicella infection is somewhat higher in adults, children living with HIV have a significant mortality rate from primary varicella infection and may also develop severe complications.
Clinical presentation
The cutaneous presentation of primary and secondary VZV in patients with HIV commonly follows a typical course, with crops of pruritic papules and vesicles on an erythematous base that become generalised in primary varicella and follow a dermatomal distribution in HZ. (30) In the setting of more advanced HIV infection, primary varicella is often more florid with a pronounced systemic prodrome (malaise, headache, fever and myalgia), has a prolonged course, and has a greater incidence of systemic complications such as encephalitis, pneumonitis and hepatitis. (30)
The classical rash of HZ is grouped vesicles or bullae, involving one or more dermatomes, evolving into pustular and haemorrhagic lesions within a few days. Most patients have prodromal pain in the affected dermatome preceding vesicular eruption. Disseminated HZ is defined by more than 20 vesicles outside the area of the primary and adjacent dermatomes or those involvement over three contiguous dermatomes, and is rare but has been reported in the setting of advanced HIV infection. (31) Subsequently, crusting occurs with the development of hypo- or hyperpigmentation as well as atrophic scarring. (32) The diagnosis of HZ in the distribution of the ophthalmic division of the trigeminal nerve is important, as it can cause uveitis and keratitis.
Following resolution of HZV, 5-20% of patients may develop post-herpetic neuralgia, characterised by persistent burning pain or allodynia in the affected dermatome. (33, 34)