Herpes zoster - Anogenital in
Cutaneous herpes zoster usually begins with a 1-3 day prodrome of burning pain or paresthesias in the affected dermatome, followed by eruption of erythematous papules and vesicles in the same distribution.
Involvement of a thoracic dermatome may simulate acute myocardial infarction. Involvement of the ophthalmic branch of the trigeminal nerve may lead to herpes zoster ophthalmicus. Herpes zoster oticus (Ramsay Hunt syndrome) occurs with involvement of the vestibulocochlear nerve. Disseminated zoster, defined as >20 vesicles outside of the primary and adjacent dermatomes, is chiefly a problem of immunocompromised patients (HIV patients, cancer patients, and those on immunosuppressive drugs).
A major concern after a zoster outbreak is the postherpetic neuralgia (PHN), defined as pain and neuropathic symptoms that persist in a dermatome one month beyond resolution of the rash. Risk factors for PHN include older age, female sex, presence of a prodrome, and greater rash severity and acute pain. Postherpetic neuralgia can be intractable and debilitating, and prevention is an important goal.
Cerebrovascular accidents, peripheral motor neuropathies, neurogenic bladder, and diaphragmatic paralysis have been associated with zoster. Herpes zoster encephalitis usually appears in the first 2 weeks after the onset of lesions and it has a 10%-20% mortality rate. Lesions may also be at risk for bacterial superinfection. In extreme cases, necrotizing fasciitis may occur.
B02.9 – Zoster without complications
4740000 – Zoster
- Cellulitis or erysipelas
- Disseminated varicella can occur, particularly in the immunocompromised.
- Herpes simplex virus infection
- Allergic contact or irritant contact dermatitis
- Insect bites
- Molluscum contagiosum
- Other poxviruses (cowpox, monkeypox)
- Pyoderma gangrenosum
- Primary varicella infection
- During the prodromal phase, herpes zoster pain may mimic acute myocardial infarction or biliary colic.
- Bullous fixed drug eruption
- Eczema herpeticum
- Sweet's syndrome
- Fournier gangrene