Supplementary Material for: Lupus Erythematosus Tumidus Misdiagnosed as Erythema Nodosum from Coccidioidomycosis

Introduction
Lupus erythematosus tumidus (LET) is a rare photosensitive dermatosis that is categorized as intermittent cutaneous lupus erythematosus. It shares clinical similarities and histopathological features with other skin disorders, such as erythema nodosum, lymphocytic infiltrate of Jessner and reticular erythematous mucinosis, thus making diagnosis quite challenging. We present a patient with LET whose diagnosis was confirmed after seeing several doctors.
Case Presentation
A 52-year-old Hispanic female presented with tender erythematous nodules on her thighs for approximately one month. She was suspected of having erythema nodosum secondary to coccidioidomycosis and was prescribed fluconazole 200 mg for 30 days but showed no improvement. However, histopathological and direct immunofluorescence tests later confirmed a diagnosis of LET. The patient was treated with hydroxychloroquine and the lesions improved remarkably after two weeks.
Conclusion
LET is a rare dermatosis that closely resembles other dermatologic conditions such as erythema nodosum, and lymphocytic infiltrate of Jessner and reticular erythematous mucinosis. Diagnosis based on clinical features alone should be avoided, and ideally, treatment should only be initiated after confirmatory histopathological testing.

引言
肿性红斑狼疮（Lupus erythematosus tumidus，LET）是一种罕见的光敏性皮肤病，归类为间歇性皮肤狼疮。其临床特征与组织病理学表现均与结节性红斑、杰斯纳淋巴细胞浸润症及网状红斑性粘蛋白病等其他皮肤病症存在相似性，因此诊断颇具挑战性。本文报告一例经多名医师诊治后方确诊的LET患者。

病例报告
一名52岁西班牙裔女性，因大腿出现触痛性红斑结节约1个月就诊。最初临床怀疑为球孢子菌病继发的结节性红斑，予氟康唑200mg口服治疗30天，但症状无改善。后续经组织病理学及直接免疫荧光检查，最终确诊为LET。予羟氯喹治疗后，皮损在两周内显著好转。

结论
肿性红斑狼疮是一种罕见皮肤病，与结节性红斑、杰斯纳淋巴细胞浸润症及网状红斑性粘蛋白病等其他皮肤病症表现高度相似。临床工作中应避免仅依靠临床表现进行诊断，理想情况下应在组织病理学确诊后再启动治疗。