A rash diagnosis

Morning report discussed a case of a patient who presented with non specific symptoms such as nausea, vomiting, subjective fevers, and back pain.

Based on this, proposed diagnoses based on symptom/syndrome recognition included pyelonephritis, vertebral osteomyelitis, epidural abscess. 

If the patient was delirious, how would your consideration change?
Perhaps age factors into this and would be appropriate if this were a patient who was elderly with vascular injury in the past. 

Delirium might invoke CNS infections, or may be secondary to the primary process. 

Physical examination revealed a vesicular rash, in a dermatomal distribution. 

These lesions were de-roofed and sent for analysis, which came back as VZV.

VZV:

Primary infection with VZV = Chicken Pox. Latency develops in dorsal nerve roots.

Reactivation then occurs: 

-Can be with rash = shingles, dermatomal distribution

-Can be without rash = zoster sine herpete

-Reactivation can present with or without visceral involvement eg. pancreatitis, hepatitis

Age is the biggest risk factor on a population basis for reactivation.

Neurologic complications of VZV include:

-         Zoster opthalmicus

-         Bell’s Palsy

-         Ramsay Hunt

-         Immunocompetent: can develop

o       Transverse myelitis

o       Granulomatous angiitis – can present as stroke

-         Immunocompromised:

o       Transverse myelitis

o       Small vessel vasculopathy – present as encephalitis

-         POST HERPETIC NEURALGIA

o       Post herpetic neuralgia defined as pain > 90 days after onset of rash. Age again  is RF.

Zoster associated pain comprises phase of acute neuritis and post herpetic neuralagia

 Antivirals

-         Acyclovir, Famcyclovir, Valcyclovir. (FCV,VCV may be considered over ACV because of activity, dosing)

-         Decrease rash by 0.5 day, decrease fever by 0.5 day, decrease acute neuritis phase

-         Treatment should be within 72 hours of rash. Exceptions include zoster opthalmicus, immunocompromised, one could argue for Bell's Palsy.

Post Herpetic Neuralgia treatment

-         gabapentin, TCA’s...no clear direction over which to choose, which is better. Acetaminophen, NSAIDs may help.

Other points in management include getting an ophtho assessment if V1 is involved. The role of steroids is controversial.

Zostavax

-         Indicated for greater than 60 yo

-         50% reduction in shingles

-         67% reduction in zoster associated pain

-         Similar results greater than 50 yo

-         Cannot give if on immunosupression. Should wait at least 6 months

-         Not clear when to give after acute zoster infection…

For more details see this NEJM review article on Zoster

...and this NEJM article on neurologic complications of Zoster