Incidence of and Risk Factors for Cutaneous Scarring after Herpes Zoster.

Background: About 20% of children have cutaneous scars following chickenpox. In contrast, skin scars are not often reported after herpes zoster (HZ). Risk factors for post-HZ scarring remain undetermined.

Objective: Our objective was to prospectively study the incidence of and risk factors for post-HZ scarring.

Methods: This was a 3-year prospective study of patients with HZ attending a tertiary university hospital. Baseline data, including age, sex, immunosuppression, prior history of scarring, severity and extension of HZ, afflicted HZ dermatome, and antiviral treatment received, were recorded. At 1 month after the HZ skin lesions had healed, patients were screened for skin scars at the prior HZ site. These patients were followed every 2 months for 6 months.

Results: At 6 months, 11 (9.7%) of 113 HZ patients still had post-HZ scarring (fair-skinned patients: hypopigmented [n = 3], hyperpigmented [n = 2], atrophic cicatricial [n = 3], and hypertrophic cicatricial [n = 1]; dark-skinned patients: severe hyperpigmented hypertrophic scarring [n = 2]). HZ was extensive and severe in all cases. Nine of the 11 patients were immunocompromised. Three cases had a history of hypertrophic/keloid scarring but no post-varicella scars. The most frequent location was the trunk (n = 5), followed by the cervical region (n = 3) and the face (n = 3). Given the study setting, it is possible that immunocompromized patients with severe HZ were overrepresented in this study.

Conclusions: Scarring after HZ is probably overlooked. The principal risk factors seem to be severe HZ and immunosuppression. Hence, prompt instigation of antiviral treatment for HZ and HZ vaccination could help reduce the incidence of post-HZ scarring.