For personal use. Only reproduce with permission from The Lancet Publishing Group. THE LANCET Infectious Diseases Vol 3 February 2003 http://infection.thelancet.com 87 Post-kala-azar dermal leishmaniasis (PKDL) is a complication of visceral leishmaniasis (VL); it is characterised by a macular, maculopapular, and nodular rash in a patient who has recovered from VL and who is otherwise well. The rash usually starts around the mouth from where it spreads to other parts of the body depending on severity. It is mainly seen in Sudan and India where it follows treated VL in 50% and 5–10% of cases, respectively. Thus, it is largely restricted to areas where Leishmania donovani is the causative parasite. The interval at which PKDL follows VL is 0–6 months in Sudan and 2–3 years in India. PKDL probably has an important role in interepidemic periods of VL, acting as a reservoir for parasites. There is increasing evidence that the pathogenesis is largely immunologically mediated; high concentrations of interleukin 10 in the peripheral blood of VL patients predict the development of PKDL. During VL, interferon  is not produced by peripheral blood mononuclear cells (PBMC). After treatment of VL, PBMC start producing interferon , which coincides with the appearance of PKDL lesions due to interferon--producing cells causing skin inflammation as a reaction to persisting parasites in the skin. Diagnosis is mainly clinical, but parasites can be seen by microscopy in smears with limited sensitivity. PCR and monoclonal antibodies may detect parasites in more than 80% of cases. Serological tests and the leishmanin skin test are of limited value. Treatment is always needed in Indian PKDL; in Sudan most cases will self cure but severe and chronic cases are treated. Sodium stibogluconate is given at 20 mg/kg for 2 months in Sudan and for 4 months in India. Liposomal amphotericine B seems effective; newer compounds such as miltefosine that can be administered orally or topically are of major potential interest. Although research has brought many new insights in pathogenesis and management of PKDL, several issues in particular in relation to control remain unsolved and deserve urgent attention. Lancet Infect Dis 2003; 3: 87–98 Post-kala-azar dermal leishmaniasis (PKDL) is a complication of visceral leishmaniasis (VL). VL, also known as kala-azar, is caused by species of Leishmania that are transmitted by the bite of a female sandfly, and it is estimated that 200 million people are at risk for the yearly 500 000 cases. 1 Most cases occur on the Indian subcontinent (India, Nepal, Bangladesh) and east Africa (Sudan, Ethiopia, Kenya), where Leishmania donovani is the causative parasite. Whereas VL is considered to be anthroponotic in India with people as the only known reservoir, in other areas the picture is less clear and transmission may be anthroponotic as well as zoonotic, with rodents and canines as candidate reservoirs. Other VL endemic areas include countries in the Mediterranean basin, where Leishmania infantum is the species involved, and the New World, where the identical Leishmania chagasi circulates; in both areas canines are the reservoir hosts. Key features in the clinical presentation of VL are prolonged fever, hepatosplenomegaly, and weight loss. Dependent on the geographical region, in L donovani endemic areas between 5% and 60% of patients develop a dermatosis called post-kala- azar dermal leishmaniasis (PKDL) during or after treatment. This skin condition has a tendency to become chronic and is characterised by macular, papular, or nodular lesions in which leishmania parasites may be seen. PKDL is therefore considered a reservoir for leishmania parasites, especially during interepidemic periods of VL. Although the condition has been described for about 80 years, only recently has its relevance, in particular in Africa, been fully recognised. Recent studies have provided new insights into the pathogenesis of this condition that has important clinical and epidemiological implications. Clinical features The clinical features have been best described in reports from Sudan and India and are summarised in table 1. Review Post-kala-azar dermal leishmaniasis EEZ is at the Department of Medicine, College of Medicine, Malawi; AMM, EAGK, and AMEH are at the Department of Immunology and Clinical Pathology, and IMEH is at the Department of Parasitology and Medical Entomology, Institute of Endemic Diseases, Khartoum, Sudan. Correspondence: Dr EE Zijlstra, Department of Medicine, College of Medicine, Private Bag 360, Chichiri, Blantyre 3, Malawi. Tel +265 1 670202 or +265 8 844318; fax +265 1 673933 or 674700; email eezijlstra@malawi.net Post-kala-azar dermal leishmaniasis E E Zijlstra, A M Musa, E A G Khalil, I M El Hassan, and A M El-Hassan Figure 1. PKDL papular lesions.