Droplets from the nose and mouth of untreated patients are the primary route of transmission of the chronic infectious disease known as leprosy, which is caused by Mycobacterium leprae or Mycobacterium lepromatosis. However, it is challenging to distinguish leprosy from other diseases that cause skin lesions because there are no reliable serological markers or distinctive clinical signs.

This case report presents and summarizes the diagnosis and treatment of a case of leprosy that was initially misdiagnosed as erythema multiforme. A female patient, age 43, was admitted to the facility in May, reporting “repeated fever with superficial lymphadenopathy and widespread rash.” Multiple lymph nodes and skin biopsies, routine pathological examination, immunohistochemistry, acid-fast, silver hexamine, periodic acid-Schiff (PAS), and second-generation gene sequencing of fresh biopsy tissue, all contributed to the patient’s diagnosis, which was based on the 2 key clinical characteristics of superficial lymphadenopathy and systemic pleomorphic erythema.

At the Institute of Dermatology and Venereal Diseases, the patient has been given the antibiotics dapsone, rifampicin, and clofazimine. As a result, her normal body temperature was restored after a year of medication, the redness in her face lessened, and the size of her axillary lymph nodes steadily shrank. Ultimately, second-generation gene sequencing and specialized pathological labeling indicate advantages in differentiating leprosy from other skin lesion-related disorders.

Source: ann-clinmicrob.biomedcentral.com/articles/10.1186/s12941-022-00532-4