Post-herpes zoster sarcoidosisDear Editor, Post-herpetic isotopic reactions induce various skin conditions on healed sites, and several possible mechanisms such as viral, immunological, vascular and neural etiology are proposed in this process. We herein report a case of sarcoidosis on the sites of herpes zoster.A 72-year-old man was suffering from diabetes mellitus, hypertension and hyperlipidemia. He developed herpes zoster on the trunk, and was treated with antiviral drugs (acyclovir 4000 mg/day for 7 days) in a nearby clinic. Three months later, asymptomatic eruptions appeared on the healed herpes zoster sites. He also complained of weight loss, night sweats and general fatigue. Physical examination revealed infiltrative erythematous papules on the left lower back, with distribution coinciding with herpes zoster-affected areas ( Fig. 1a). A biopsy specimen revealed non-necrotizing, epithelioid granulomas located in the mid-to lower dermis with minimal lymphocytic infiltration ( Fig. 1b). Detailed clinical examination revealed scar sarcoidosis on the knees, and additional biopsy also showed sarcoid granuloma in the dermis. Laboratory examination showed liver dysfunction, increased serum levels of angiotensin-converting enzyme (39.9 U/L; normal range, 7-25) and soluble interleukin-2R (4930 U/mL; normal, 124-460). However, antinuclear antibody was negative. Chest X ray revealed bilateral hilar lymphadenopathy, and computed tomography showed lymph node adenopathy in the lung and porta hepatis. No abnormalities were detected on cardiac or ophthalmological examination. Porta hepatic lymph node biopsy did not reveal lymphoma. Bone marrow biopsy showed granulomatous changes with multinucleated giant cells (Fig. 1c), however, lymphoma was not detected.We described a case in which cutaneous sarcoidosis developed on the herpes zoster-affected sites. Detailed investigation revealed scar sarcoidosis on the knees, and systemic investigation revealed lung sarcoidosis. Because our patient complained of persistent slight fever, weight loss, night sweats and multiple lymphadenopathy, bone marrow aspiration was carried out under suspicion of lymphoma (sarcoidlymphoma syndrome). The results showed no atypical cells, but granulomatous features were detected in the bone marrow, suggesting bone marrow involvement of sarcoidosis. Also, lymph node biopsy denied malignant lymphoma. Diagnosis of sarcoidosis was made on the occasion of cutaneous lesions following herpes zoster. Therefore, we conclude that our patient developed systemic sarcoidosis prior to the onset of herpes zoster, and cutaneous sarcoidosis was induced at the site of herpes zoster. Isotopic and isomorphic response sometimes overlap in multicentric systemic diseases, 1 which is true of our case. To date, several cases of post-herpes (a) (b) (c) Figure 1. (a) Clinical appearance showing brownish papules with zosteriform distribution. (b) Histological features showing sarcoid granuloma in the lower dermis. (c) Granuloma formation in the bone marrow (hematoxylin-eosin, or...