Herpes zoster itch: preliminary epidemiologic data

The best-known complication of shingles (herpes zoster) is postherpetic neuralgia (PHN). PHN is commonly studied to investigate causes of and treatments for neuropathic pain. However, many patients with shingles experience neuropathic itch accompanying, or instead of, pain. Some report severe disabling postherpetic itch (PHI), and though it is rare, some patients injure themselves by scratching itchy skin that has lost protective sensation. To date, there is virtually no mention of PHI in the medical literature; neither epidemiologic, anatomic, physiologic, nor treatment studies. We analyzed 3 independent existing sets of data from 586 adults with shingles or PHN to glean epidemiologic information about pruritus during and after shingles. All data refer to itch localized to shingles-affected areas and initiated by shingles. They indicate that pruritus, usually mild or moderate, commonly accompanies both acute zoster and PHN. There was no significant difference in age between subjects with and without PHI. In one group, but not in another, there was an increased number of women with PHI. Subjects whose shingles affected the head, face, and neck were more likely to experience PHI than those whose shingles affected the torso. These findings indicate a need for research on zoster-associated itch, including prospective studies on frequency, impact, and treatment.