Pediatric Autoimmune Hepatitis in a Patient Who Presented With Erythema Nodosum: A Case Report

BACKGROUND: Autoimmune hepatitis (AIH) is a form of chronic hepatitis with unclear causative factors and is characterized by immunological and auto-immunological manifestations. Several extrahepatic manifestations, such as other autoimmune disorders, are associated with AIH. AIH with dermatological conditions as the initial manifestation is rare. We report the case of AIH in which erythema nodosum (EN) was the first manifestation. CASE PRESENTATION: An 8-year-old girl with several persistent dermatological lesions was referred to our hospital several months ago. Her skin had nodular, painful, dry, and erythematous lesions, predominantly on the extensor areas of both the legs, with some erythematous patches on her face. Physical examination revealed that she had hepatosplenomegaly as well. Skin biopsy indicated EN. The results of the laboratory tests showed increased levels of several liver enzymes. The patient's International Autoimmune Hepatitis Group (IAIHG) score was a definite indicator of AIH. The results of liver biopsy indicated AIH. Other causes of EN and abnormal liver function were ruled out. The only obvious cause of skin lesions was chronic inflammation due to an autoimmune response. The patient was treated for AIH, and her skin lesions along with other signs and symptoms resolved. CONCLUSIONS: AIH can present with protean clinical manifestations, and is thus associated with the risk of delayed diagnosis. Dermatological manifestations, including EN, could indicate a serious disease, and further investigation might be required. AIH should be considered as the possible diagnosis in such cases.