Autoimmune Hemolytic Anemia due to Varicella Infection

Varicella is usually benign exanthematous disease, which primarily affects children. The common complications are bacterial infection of skin eruptions, pneumonia, cerebellar ataxia, hepatitis, thrombocytopenia and arthritis [1]. Autoimmune hemolytic anemia (AIHA) is a rare complication of varicella and only few cases are reported [2-5]. Overall the incidence of AIHA in children is as low as 0.2/100,000 population [3]. We report AIHA due to chickenpox in a child who responded to steroids. An 11 year old female was brought with fever of one day followed by pleomorphic skin lesions of 8 days and jaundice of 2 days duration. Her urine and stools were normal. She was conscious, temperature was 37.8 ° C, HR 160/min, RR 32/min, BP of 90/60 mmHg and SpO2 was 90% in room air. On examination, she had severe pallor and jaundice. There were multiple vesicular and scabbed skin lesions of chicken pox all over the body. There was no evidence of bleeding tendencies, bony tenderness or lymphadenopathy. Abdominal examination revealed 3 cm hepatomegaly and 1 cm splenomegaly. The rest of the examination was unremarkable. Laboratory investigations: Hb 3.8 g/dL RBC count 1.84×10 6 /L, total leucocyte count 12.1×10 9 /L (polymorphs 88%, lymphocytes 10%, eosinophils 2%), platelet count 303 ×10 9 /L and reticulocyte count 0.5%. RBC indices (MCV, MCH, MCHC) were normal. Peripheral smear showed normocytic normochromic anemia with clumping of RBCs. The Direct Coombs test using polyspecific anti-IgG and anti-C3b/C3d Complement antihuman globulin reagent was positive. Cold agglutinins were not detected and indirect Coombs Test was negative. Total serum bilirubin was 15.5mg/dL (direct bilirubin 1.3mg/dL), SGOT 30 U/L, SGPT 44 U/L, Alkaline phosphatase 123 U/L, total protien 8.5g/L, serum albumin 4.2g/L and serum LDH was 1580 U/L [Normal 230-460 U/L]. Renal function tests and blood sugar were within normal limits. Urine examination was negative for blood, bile salts, bile pigments and microscopy was normal. Urinary urobilinogen was not increased. Hemoglobin electrophoresis was normal. In view of severe pallor, jaundice, classical chicken pox lesions, positive Direct Coombs test, indirect hyperbilirubenemia and elevated LDH values, a diagnosis of varicella AIHA was made and three units of packed RBCs transfused. On the third day of admission, her vitals were normal, Hb was 12.2 g/dL, and reticulocyte count 1%. On the fourth day she developed pallor, Hb dropped to 7.8 g/dL and reticulocyte count was 1.5%. Other investigations: Serology for IgM varicella, IgM anti HAV, HbsAg, Anti HCV, Anti …