Subclinical Hypothyroidism as a Possible Cause of Herpes Zoster Reactivation

Abstract

Background: Hypothyroidism was considered as a predisposing factor for herpes zoster (HZ) infection. Thus, Thyroxine deficiency may be a risk factor for varicella zoster virus reactivation. The aim of this study was to test if thyroid hormone supplementation will ameliorate the clinical course of HZ infection.

Methodology: This was a prospective cohort conducted on 60 herpes zoster infected patients, who had a subclinical hypothyroidism. Serum TSH and FT4 measurements were made by using electrochemiluminescence immunoassay. All patients were divided into two groups. Group A included 30 patients who were treated with Eltroxin 25 µg daily for 3 months. Group B included 30 patients who took placebo. All were submitted to cutaneous examination (e.g., rash and new lesions). Any complications were documented. Pain was assessed before and after treatment, and any pain-controlling medications were registered. The primary endpoints were time to achieve complete pain cessation, time to cessation of the formation of the new lesions, and time to > 50% crusting/healed lesions. Secondary outcome included time to 100% crusting/healed lesions, time to complete absence of moderate to excruciating pain, time to first pain-free period, and time to absence of abnormal sensations.

Results: Both groups were comparable regarding patient age, gender, chronic medical diseases, and characteristics of herpes zoster rash. Ophthalmic zoster was reported in 6.7% and 10% of groups A and B respectively. However, group A (Eltroxin supported) had much better and rapid and rash healing of pain than group B. Finally, zoster-related complications were significantly lower in group A than group B.

Conclusions: Subclinical hypothyroidism is associated with HZ reactivation process, so hypothyroid medical treatments are effective in this case.