Cutaneous onchocerciasis in Dumbu, a pastoral area in the North-West region of Cameroon: diagnostic challenge and socio-economic implications.

Onchocerciasis is a severe parasitic infestation caused by Onchocerca volvulus which causes disabling skin and subcutaneous tissue changes and ultimately leads to blindness. It has a huge public health impact due to its socioeconomic burden and the vast number of people it affects in developing countries. In this case, a 60 years old woman was encountered with leopard skin like changes, rashes and pruritus on the left leg; which had been managed as cutaneous mycosis for over a period of 8 years. A diagnosis of onchocerciasis was finally made after a skin snip identified onchocercal microfilariae. The above case shows that onchocerciasis is still a neglected tropical disease (NTD) in Cameroon. This emphasizes the need for more expansive outreach programs in remote areas in Cameroon, a change in health policies to ensure the eradication of this disabling disease and health promotion amongst vulnerable populations.

Comparative assessment of enzyme-linked immunosorbent assay and Western blot for the diagnosis of toxocariasis in patients with skin disorders.

Background The link between various chronic skin disorders and toxocariasis was previously demonstrated by case reports and several case-control studies. However, these previous studies were based only on the Toxocara canis excretory-secretory-enzyme-linked immunosorbent assay (TES-ELISA) serological technique, which is not specific due to cross-reactivity with parasites of the genera Anisakis or Ascaris. Immunoblot analysis is highly specific and can detect very low levels of Toxocara antibodies. Therefore, this technique may be useful in the identification of Toxocara infection in patients with chronic skin disorders. Objectives Because urticaria and pruritus/prurigo are skin conditions previously associated with toxocariasis, we carried out a prospective study using both TES-ELISA and Toxocara Western blot on 113 patients with either chronic urticaria (n = 84) or chronic pruritus (n = 29). Methods Patients were matched with controls according to gender, age and residence location (rural or urban area). Data were analysed using a Mantel-Haenszel chi(2) test. Results The proportion of positive TES-ELISA results was not significantly different for patients with chronic skin disorders (urticaria or pruritus/prurigo) from that of control subjects. However, the proportion of positive immunoblot results was significantly higher for patients with chronic urticaria than for control subjects (P = 0.009). Conclusions Our study demonstrates the need to perform Western blotting immunodiagnosis, whatever the TES-ELISA result, to improve diagnosis of human toxocariasis in patients with chronic urticaria caused by Toxocara infection.