A 40-year-old male with a past medical history of HIV presented for evaluation of a non-pruritic rash. Six days ago, he suddenly felt a stinging sensation at the back of his head and neck similar to a bug bite. He then noticed bumps were starting to form and developed a shock-like pain in the area. Three days ago, the rash spread from the back of his head towards his chest. Yesterday, the rash spread further and now extends medially and upwards covering most of his left neck and ear. The pain continued to worsen, at which point the patient shaved the left side of his head in an attempt to help the rash. Today, the pain became unbearable, which prompted his visit to the emergency department for further evaluation and management.
Head: Normocephalic, atraumatic; left side of patient’s head is shaved.
Eye: Pupils equal, round, reactive to light; extraocular movements intact; no corneal ulcers or dendritic lesions with fluorescein staining.
Visual acuities: Right 20/25, left 20/25, baseline 20/25
Ear, nose, throat: Mucous membranes are dry; oral thrush and tonsillar erythema appreciated; localized erythema, crusting and blistering rash of varying sizes and ages along with the outer ear including the tragus, antihelix, and antitragus; helix mildly swollen. On otoscopy, the tympanic membranes appear pearly grey, shiny, translucent with no bulging, and without cerumen impaction.
Neck: Full range of motion appreciated but both horizontal and vertical movement is slow secondary to pain; no lymphadenopathy.
Neurological: Awake, alert, and oriented to date, place, and person; moves all extremities; cranial nerves II through XII grossly intact; strength 5/5 in all extremities; gait steady; no ataxia, dysmetria, or dysarthria.
Skin: Erythematous, localized, crusted, blistering vesicular rash of various sizes and ages appreciated along the left V3 distribution, C3 to T3 dermatomes anteriorly, and C2 to C6 dermatomes posteriorly.
The lesions can be characterized as vesicles in various stages of healing. Some lesions are crusted, others are bullous, and a few are pustular. The C2-C6 dermatomes are affected posteriorly, and the C2-T3 dermatomes are involved anteriorly.
The diagnosis is Disseminated Herpes Zoster. The rash in reactivation varicella zoster virus (VZV) is preceded by tingling, itching, or pain, and begins as maculopapular then progresses to vesicles, pustules, and bullae. The rash typically involves a single dermatome and does not cross the midline. Rash present in multiple dermatomes (>3) or a rash that crosses the midline signifies disseminated disease. Hutchinson’s sign is a lesion on the lateral dorsum and tip of the nose indicating the involvement of the nasociliary branch of the ophthalmic division of the trigeminal nerve. The nasociliary branch innervates the eye, thus these lesions are highly suspicious for herpes zoster ophthalmicus. Herpes zoster ophthalmicus on fluorescein examination appears as pseuododendritic lesions with no terminal bulbs (not to be confused with herpes simplex virus (HSV) keratitis, which has dendritic lesions with terminal bulbs). Vesicles in the auditory canal (herpes zoster oticus) may be a part of Ramsay Hunt syndrome with ear pain and paralysis of the facial nerve.
The patient is immunocompromised and requires hospitalization for intravenous (IV) antiviral therapy and pain management. VZV primary infection results in viremia, diffuse rash, and seeding of sensory ganglia where the virus establishes latency. Herpes zoster is the result of viral reactivation with spread along the sensory nerve in that dermatome. Antiviral therapy aids in the resolution of lesions, reduces the formation of new lesions, reduces viral shedding, and decreases the severity of acute pain, but does not affect the development of post-herpetic neuralgia.
Immunocompetent patients may receive Valacyclovir 1 g PO q8hrs (preferred) or Acyclovir 800 mg PO 5x/day x 7d if the onset of rash is <3 days or >3 days with the appearance of new lesions.
Immunocompromised, transplant, and cancer patients are all at high risk for dissemination, chronic skin lesions, acyclovir-resistant VZV, and multi-organ involvement. Immunocompromised patients and patients with disseminated zoster require aggressive multimodal treatment, admission to the hospital, and IV antiviral therapy regardless of the time of onset of rash. Recommended therapy is Acyclovir 10 mg/kg IV q8h or Foscarnet 40 mg/kg IV q8h for acyclovir-resistant VZV. All patients require adequate analgesia, typically with non-steroidal anti-inflammatory drugs, opioids, Gabapentin, Nortriptyline, and Lidocaine patches on intact skin.