Case of the Week

Editor: Dr Danielle Coleman

This is tumbu (or Putsi) fly (cordylobia anthropophaga) myiasis. The female tumbu fly normally lays its eggs on the ground, or on the fur of animals. However it will also lay eggs on clothing left out to dry. The eggs hatch in two or three days, and the larva penetrates the skin where it gradually enlarges over the next 12 days. It creates a small opening to the surface for breathing and to release waste products. If not disturbed the larva will enter the pre-pupal stage at which point it will emerge from the skin and drop to the ground to complete pupation. The patient notices a gradually enlarging and uncomfortable red spot, which comes to resemble a boil. However the small breathing opening can usually be identified. This fly is commonest in East Africa, but occurs throughout sub-Saharan Africa.

The treatment is to apply Vaseline (petroleum jelly) or similar to completely cover the breathing opening. A small four sided elastoplast is a good way to keep the Vaseline in place. The larva will try to fight its way up to the air, extruding itself entirely through the opening onto the skin. This process may be uncomfortable.

The best way to avoid this condition is to ensure that all clothing worn next to the skin is ironed after drying, if it has been left out in the open in an endemic area.