What severe complication can result from a threadworm infestation?

A severe complication that can result from a threadworm infestation, specifically caused by Strongyloides stercoralis, is pneumonia or liver abscesses. In immunocompromised individuals, the threadworm can undergo autoinfection, leading to an overwhelming infection that disseminates throughout the body, affecting multiple organs.

When the larvae migrate through the bloodstream, they can accumulate in the lungs, leading to respiratory complications such as pneumonia. This could manifest as symptoms of cough, shortness of breath, and chest pain. Additionally, if the infection spreads to the liver, it could form liver abscesses, causing abdominal pain and potentially fever, which are serious conditions requiring prompt medical attention.

The other options provided do not typically arise from threadworm infestations. Conjunctivitis is primarily associated with viral or bacterial infections affecting the eyes, cardiovascular failure is more commonly linked to heart conditions rather than parasitic infections, and skin lesions could occur from various causes but are not a severe complication specifically of threadworm infections. Thus, the risk of pneumonia or liver abscesses highlights the serious nature of complications that can arise from chronic or disseminated threadworm infestations.