MED2 Kikuchi's disease: An uncommon cause of fever of unknown origin. (Medicine).

MED2 KiIKUCHI'S DISEASE: AN UNCOMMON CAUSE OF FEVER OF UNKNOWN ORIGIN. Tahir Abmad, MD, Scott Sheldon, MD, and Mukta Panda, MD. Department of Medicine, University of Tennessee, Chattanooga.

Fever of unknown origin (FUO) can be a diagnostic dilemma requiring extensive workup. Kikuchi's disease or histiocytic necrotizing lymphadenitis is an uncommon cause of FUO. It lacks specific signs, symptoms, and serologic markers and can mimic many clinical scenarios. A 34-year-old black man presented with a low-grade fever, night sweats, generalized fatigue, weakness, and myalgias of 2 weeks' duration. He had a waxing and waning rash on the face and anus. His medical history was significant for hypertension since age 26 and a similar rash and fever about 12 years ago. On examination, he was febrile (temperature of 103[degrees]F) and tachycardiac. Physical examination was unremarkable except for one 2 x 2 cm right submandibular lymph node, a few lymph nodes in the right posterior cervical triangle and a hyperpigmented maculopapular skin rash involving the upper extremities and the face. The laboratory data showed WBC 2,000/[mm.sup.3], hemoglobin 8.4 g/dL, hematocrit 25.8%. The blood cultures, urine cultures, chest x-ray, imaging studies of the bead, neck, thorax, and abdomen were all negative. ESR: 98, high CRP 8.4 mg/dL. Rheumatologic workup, viral and rickettsial serology, RPR, and HIV were negative. Bone marrow biopsy and culture was also negative. The right submandibular lymph node biopsy showed histiocytic necrotizing lymphadenitis. He was started on vioxx for the fever and myalgia. The patient's fever subsided after 5 weeks. He returned with vision problems and was found to have retinal hemorrhages bilaterally. Steroids were initiated for ocular symptoms. Kikuchi's disease Was first described in Japan in 1972 by Kikuchi and Fujimoto. It is a self-limiting disease involving different ages, races, and geographic regions. The cause of this disease is uncertain, though its association with certain pathogens like CMV, EBV, HSV, Parvo B-19, HIV, Yersinia, and Toxoplasmos has been described. These or other antigens can induce immunologic abnormalities in a susceptible individual with progression to autoimmune diseases like SLE and Still's disease. The most common clinical features of Kikuchi's disease are fever, weakness, fatigue, myalgia, arthralgia, and lymphadenopathy (especially in the cervical region). Skin rash is noncharacteristic ranging from nodules, papules, maculopapular erythema, or urticaria particularly involving the upper regions of the body. Hepatosplenomegaly and neurologic manifestations like aseptic meningitism and ataxia have also been described. However, this is the first case described with retinal changes. Kikuchi's syndrome needs to be differentiated from other diseases like malignant lymphoma, SLE, tuberculosis, sarcoidosis, and cat scratch disease. Since the course of Kikuchi's disease generally self-limited and histopathology is diagnostic, it is important to include it in the differential diagnosis of FUO. There is no specific treatment. NSAIDs usually suffice, but in complicated cases, use of immunosuppressives and steroids have been recommended to prevent fatal outcome.