Choose the correct association of a skin condition with its usual location.

The association of scabies with its usual locations—fingers, wrists, and waist—accurately reflects the typical areas where this infestation occurs. Scabies is caused by the Sarcoptes scabiei mite, which burrows into the skin, causing intense itching and a rash. The fingers and wrists are commonly affected because they are areas where skin-to-skin contact often occurs, facilitating the transmission of the mites. The waist can also be affected especially in areas where clothing fits tightly, which can create an environment conducive for the mites.

In contrast, the other associations do not align with the typical presentations of those conditions. Impetigo is usually found on exposed surfaces such as the face and arms rather than primarily on the legs and feet. Pediculosis humanus corporis, or body lice, is primarily associated with the body and clothing, not specifically the scalp, which is more characteristic of head lice (Pediculosis humanus capitis). Lastly, seborrheic keratosis typically appears on areas like the trunk, face, scalp, and neck rather than the feet and hands, which are not common sites for these benign lesions. Thus, the choice linking scabies with the fingers, wrists, and waist is accurate.