Infective dermatitis (ID) is a chronic, relapsing dermatitis associated with human T-lymphotrophic virus (HTLV)-1 which was initially described in Jamaican children. Although most cases have been reported in Jamaica, ID may be seen in other HTLV-1 endemic areas, such as Brazil, Japan, sub-Saharan Africa, and Trinidad and Tobago. Since HTLV-1 infection has been implicated in the development of adult T-cell leukemia/lymphoma, an aggressive hematologic malignancy, and HTLV-1-associated myelopathy/tropical spastic paraparesis, a neurodegenerative disease, ID may serve as an early clinical marker for either condition. Although HTLV-1-associated infective dermatitis is considered by most to be rare, it has been increasingly diagnosed over the past 20 years; some suggest ID may be underdiagnosed. One should maintain suspicion of HTLV-1 infection among individuals in or from endemic areas, recognizing the clinical features and prognostic implications of infectious dermatitis.