P79: INFECTED DERMATITIS ASSOCIATED WITH HTLV‐1: A COPYCAT FOR CHILDHOOD CUTANEOUS CONDITIONS

Abstract

Background: Infective dermatitis associated with HTLV-1 can easily be misdiagnosed as atopic dermatitis, putting patients at risk. Human TLymphotropic Virus type 1 (HTLV-1) is a single-stranded RNA retrovirus that preferentially infects CD4+ T cells. It is highly prevalent in the Australian Indigenous population. Transmission follows exposure to infected lymphocytes, which can occur via vertical and horizontal transmission, and importantly long-term breastfeeding. Infective dermatitis may not simply signal HTLV-1 infection, but is an indicator of increased risk of more devastating HTLV-1 disease complications. Known complications are rapidly progressive haematological malignancy (eg adult T-cell leukaemia/lymphoma), inflammatory disorders (e.g. myelopathy/tropical spastic paraparesis), pulmonary disease (eg bronchiectasis), as well as life threatening invasive Staphylococcal infections. Case report: Our index case is a 2-year-old Indigenous female patient, referred with recurrent 'severe infected eczema,' requiring multiple admissions. Consideration had been given to STAT3 mutation, however, extensive workup, including immunological workup, lead to the diagnosis of HTLV-1 on blood PCR. Furthermore, she fulfilled the major criteria for the diagnosis of infective dermatitis associated with HTLV-1. Since diagnosis, when compliant with appropriate treatment, response has been dramatic. Diagnosis: HTLV-1 infection is diagnosed on blood PCR. Prognostically, an HTLV-1c proviral load is essential. In addition to a blood PCR, clinical criteria for diagnosis of infective dermatitis associated with HTLV-1 requires presence of skin lesions and chronic relapsing dermatitis recurring post cessation of systemic treatment, with or without crusting of nostrils. Treatment: Treatment is aimed at controlling the complicating infections of staphylococcus aureus and beta haemolytic streptococcus. Long-term trimethoprim/ sulfamethoxazole is recommended until at least adolescence. Conclusion: Infective dermatitis associated with HTLV-1 is a clinically important mimic of other childhood dermatoses which requires high index of suspicion to ensure aggressive long term treatment to reduce morbidity and mortality.