Zoonotic hookworm infections usually result in a skin condition called cutaneous larva migrans, or CLM. When people walk or sit on beach sand or soil where infected dogs or cats have defecated, the dog or cat hookworm larva can penetrate the skin of the foot or body and migrate in the top layers of the skin. This migration causes severe itchiness and raised red lines can form as part of the reaction to the larva in the skin. The larva will die in the skin after several weeks without developing any further, and the itchiness and red lines will go away. Scratching at the lines can cause a bacterial infection. Your doctor may decide to treat you to control the symptoms and prevent a bacterial infection. In rare cases, certain types of animal hookworm may infect the intestine and cause abdominal pain, discomfort, and diarrhea.
Cutaneous larva migrans (CLM) in a patient’s foot over the course of one week. Photos courtesy of Florida Department of Health, Duval County Epidemiology