Intense itching ("pruritus") and rash caused by an allergic reaction to louse bites are common symptoms of body lice infestation. As with other lice infestations, intense itching leads to scratching which can cause sores and secondary bacterial infection of the skin.

When body lice infestation is long lasting, heavily bitten areas of the skin can become thickened and darkened, particularly in the mid-section of the body. This condition is called "vagabond’s disease."

Body lice are known to transmit disease (epidemic typhus, trench fever, and epidemic relapsing fever).