[Diagnostic problems of Ornithonyssus bacoti (Acarida: Gamasida: Macronyssidae) infestation in humans]

We established an infestation with the tropical rat mite in a baby. At the beginning, the infestation was not recognized. Later it was found that it had already existed for several months, since the baby's third week. The main symptoms of the infestation were nocturnal restlessness and urticaria-like dermatitis, especially in the joint bends of the extremities. The focus of infestation were house rats (Rattus rattus) living in the garret. The Ornithonyssus bacoti mites had got into the living-room through a hole in the ceiling. Control measures against Ornithonyssus bacoti, which were successful within a short time, included eradication of the rats, closing of the hole in the ceiling, acaricide application in the garret and intensive cleaning of the living-room, the baby's nursery table, pram and bassinet.