Painful Rash in a Woman With HIV Infection

For 2 days, a 45-year-old woman has had a painful rash on her left upper chest,upper back, neck, shoulder, and upper arm; she has also had pain around herleft ear. She describes the pain as burning, needlelike, and so severe that it hasprevented sleep; it is unrelieved by topical emollients. The rash was precededby 24 hours of a similar burning pain in the same area. No neurologic deficitsare associated with the rash. She has no history of rashes; no pain or rashesoccur elsewhere on her body.HISTORY
HIV infection was diagnosed 1 year earlier. The patient is taking lamivudine/zidovudine and trimethoprim-sulfamethoxazole, and she regularly attendsan HIV clinic. She has experienced no complications of her HIV infection.PHYSICAL EXAMINATION
Lungs are clear; heart is normal. Lymph nodes are not enlarged, andthere is no hepatosplenomegaly. A maculopapular rash with a few vesiclescovers the left upper torso and upper arm in a C3-C4-C5 dermatomal distribution.There are no lesions in the ear canal or on the tympanic membrane,and no lesions elsewhere on her skin. Results of a detailed neurologic examination--except for skin pain--are normal.LABORATORY AND IMAGING RESULTS
Results of a chemistry panel are normal. Hemoglobin level and plateletcount are normal; however, the mean corpuscular volume is 110 fL. Whiteblood cell count is 4400/μL, with polymorphonuclear forms and lymphocytesin a roughly 50/50 distribution. Chest film is normal and shows no infiltrates.Which of the following is the most appropriate management strategyfor this patient?A. Do not administer acyclovir because 48 hours have elapsed since thesymptoms started.B. Administer parenteral combination therapy (acyclovir and valacyclovir)to treat disseminated herpes zoster.C. Administer corticosteroids until all lesions have completely resolved.D. Administer oral acyclovir until all lesions have completely resolved.CORRECT ANSWER: D
This patient has herpes zoster, or shingles--a reactivationof infection with varicella-zoster virus.Risk factors. Reactivation is thought to be associatedwith diminished cellular immunity. The diminution in immunitythat occurs with advancing age is responsible formost zoster cases. Thus, the incidence of herpes zosterin persons older than 75 years is 10 per 1000 person-years,and the lifetime risk of reactivation is as high as 10% to20%.^1,2Other causes of diminished immunity that predisposepatients to herpes zoster include lymphoproliferativeneoplasms (eg, lymphoma and chronic lymphocytic leukemia),immunosuppressive therapy (eg, corticosteroidsand antirejection regimens) and, as in this patient, HIVinfection. The incidence of herpes zoster in persons withHIV infection (29.4 cases per 1000 person-years) is highcompared with that in age-matched controls (2 cases per1000 person-years).² HIV infection is clearly the most commonrisk factor for herpes zoster in patients who areunder age 50.Clinical features. This patient's presentation is typical:a prodrome of neuropathic pain in the affected dermatome(s) followed 1 to 5 days later by an eruption thatis first maculopapular, then vesicular. In most patients, thediagnosis is made clinically; only rarely are studies suchas direct immunofluorescence or polymerase chain reactionused to identify the virus.In this patient, the predominant dermatome involvedis C4; there is also overflow to contiguous dermatomes.True dissemination of herpes zoster has been defined invarious ways, but according to the definition that is generallyused--more than 5 vesicles in noncontiguous dermatomes--this patient does not have disseminated infection.Thus, parenteral combination antiviral therapy fordisseminated infection¹ (choice B) is not indicated.Treatment. Several antiviral agents have been approvedfor the treatment of herpes zoster: acyclovir, valacyclovir,and famciclovir. Acyclovir is most commonlyused. Randomized controlled trials have shown that acyclovir,800 mg 5 times daily, shortens the duration of viralshedding, stops the formation of new lesions, accelerateslesion healing, and reduces pain severity.3 Data suggestthat acyclovir also decreases the incidence of postherpeticneuralgia and shortens its duration.³Oral acyclovir is as effective as intravenous acyclovirin patients who do not have disseminated herpes zoster--both those who are immunocompetent and those withHIV infection. Because oral administration permits outpatienttreatment, a 7- to 10-day course of oral acycloviris offered to most patients once dissemination has beenexcluded and an effective analgesic regimen has beenestablished.Acyclovir produces the best results when therapy isstarted within 72 hours of the onset of lesions. However,many patients seem to benefit even if treatment is startedlater, particularly if new vesicles are still emerging. Thus,choice A is incorrect. This patient presented for treatment48 hours after the rash appeared and has recently eruptedvesicles; therefore, she can be expected to benefit fromacyclovir.HIV infection is a significant risk factor for relapsefollowing acute herpes zoster. Thus, a longer courseof therapy than that used in patients without HIV coinfectionis warranted. In HIV-infected patients, oral acycloviris continued until all lesions (maculopapular, vesicular, andcrusting) have completely cleared.³ Therefore, choice Drepresents the most appropriate management strategy.Corticosteroids have a modest effect on the rate ofhealing and acute pain of herpes zoster, but no effect onthe incidence or severity of postherpetic neuralgia. If usedat all, it is recommended that they only be given concomitantlywith antiviral therapy.² Thus, choice C does not constituteoptimal treatment.Outcome of this case. Oral oxycodone, 15 mg twicedaily, was prescribed to control the patient's discomfort.Oral acyclovir was initiated, to be continued until all lesionshad healed. Once adequate analgesia was achieved,the patient was discharged to follow-up at the HIV clinic.

References:

REFERENCES:

1.

Cohen JI, Brunell PA, Straus SE, Krause PR. Recent advances in varicellazostervirus infection.

Ann Intern Med.

1999;130:922-932.

2.

Donahue JG, Choo PW, Manson JE, Platt R. The incidence of herpes zoster.

Arch Intern Med.

1995;155:1605-1609.

3.

Gnann JW Jr, Whitley RJ. Clinical practice. Herpes zoster.

N Engl J Med.

2002;347:340-346.