If the individual has never had a previous infestation, the onset of symptoms occurs two to six weeks following the initial infestation by the mite. If the individual has had a prior infestation symptoms can occur one to four days following mite infestation. The infested individual may be asymptomatic yet able to transmit the mite to others. After infestation occurs, the mite deposits eggs under the skin of the human host. After larvae hatch from the eggs, they travel to the surface of the skin.
Transmission can occur as early as two weeks after the original infestation of the individual.
A person is considered to be no longer communicable 24 hours after start of effective therapy. Erythematous papules, excoriations, or occasionally vesicles are often located between the fingers, on the upper back, wrists, elbows, thighs, breasts, or genitalia. The lesions may also appear as eczematous plaques, pustules, or nodules located in skin folds under the breasts, around the naval, axillae, buttocks, scrotum, or at the belt line on the abdomen. Infested individuals usually complain of severe nighttime itching. The itching is often worse following a hot shower or bath.