FormalPara Key Summary Points
Herpes zoster (HZ) is a painful rash caused by the reactivation of the varicella-zoster virus (VZV).
Older age, female gender, and immunosuppression are the major risk factors for virus reactivation.
Usually the rash is unilateral and is restricted to a single dermatome or to a part of it.
Bilateral rash is rare and multidermatomal HZ is more frequent in cervical dermatomes.
This is a case of a bilateral lumbar multidermatomal HZ in an elderly woman with chronic renal failure.

Case

Herpes zoster (HZ) is a painful rash caused by the reactivation of the varicella-zoster virus (VZV) permanently latent within the cranial or dorsal root ganglia after a primary childhood infection. Also known as shingles, it presents as a vesicular rash that usually affects only one side of the body, distributed in a single dermatome or restricted to a part of it [1]. In immunocompromised patients, more than one contiguous unilateral dermatome, called multidermatomal HZ, has been described, usually in cervical dermatomes [2]. Although it is unclear if VZV spreads across adjacent ganglia or to neighboring peripheral nerves, two hypothesis have been proposed to justify multidermatomal HZ propensity for cervical region: the rich innervation of cervical dermatomes covering the head and neck [3] and the shorter length of the sensory nerves of cranial and cervical dermatomes compared to thoracic or lumbar ones [2]. Bilateral non-contiguous herpes zoster, also termed herpes zoster duplex, has been reported in immunocompromised patients [4], and in a patient with end-stage renal failure [5]. Finally, one case of thoracic HZ duplex, bilateralis, and symmetricus in an immunocompetent subject has been published [6].

Besides immunosuppression, the major risk factors for virus reactivation are older age and female gender [7]. Prodromal itching, numbness, or burning sensations precede the maculopapular rash, which quickly becomes very painful. The eruption evolves to pustulation followed by ulceration and crusting [8]. Early antiviral therapy is the primary treatment of HZ, but pain management is always needed during the progression of disease until healing, usually within a month. Post-herpetic neuralgia (PHN) is the main complication of HZ occurring in 8–33% of affected patients. Once again, PHN frequency and severity increase with age [9] and may last for months or even years. Due to its poor response to analgesics, PHN can cause sleeping problems, anorexia, weight loss, and depression, compromising self-care and social life [10]. In order to avoid HZ and PHN, prophylactic vaccination has been strongly recommended in older adults [11].

This is the case of a bilateral lumbar multidermatomal HZ eruption in a 91-year-old woman with chronic kidney disease. The rash simultaneously involved bilateral dermatomes from L2 to L5 (Fig. 1). The patient complained of severe back pain, weakness in the lower limbs, and walking impairment so that her quality of life and functional status were very compromised. The patient was admitted to the hospital. Antiviral therapy was started and a pain medicine consultation was requested. Antidepressants and anticonvulsants were prescribed at low doses according to renal function, with gradual and progressive improvement of symptoms. The patient was discharged home 2 weeks later. Other than older age and kidney disease, no other risk factors were revealed.

Fig. 1
figure 1

Bilateral multidermatomal HZ rash in the lumbar dermatomes. The rash is in the phase of the formation of the crusts and dermatomal distribution is quite similar in the two sides