A nurse is teaching a group of teenage clients about the use of condoms for the prevention of sexually transmitted infections (STIs). Which of the following statements should the nurse include in the teaching?

Choice A reason:
Urine-specific gravity measures the concentration of urine compared to water. It can indicate various conditions affecting the kidneys, but it does not provide a direct measure of renal function. It can be affected by hydration status and does not specifically reflect kidney damage or disease.

Choice B reason:
Blood urea nitrogen (BUN) levels can indicate kidney health; however, BUN can also be influenced by factors such as protein intake, hydration, and liver function. Therefore, while it is a useful test, it is not the most specific indicator of renal function in isolation.

Choice C reason:
Serum sodium levels are important for assessing electrolyte balance and can be affected by kidney function. However, changes in serum sodium are not specific to kidney function alone and can result from a variety of conditions.

Choice D reason:
Serum creatinine is a waste product from the normal breakdown of muscle tissue. As the kidneys are responsible for filtering out creatinine, its level in the blood is a good indication of kidney function. Elevated levels of serum creatinine may indicate impaired kidney function or kidney disease. In the context of SLE, where kidney involvement is common, serum creatinine is a crucial marker for monitoring renal function.

Choice A reason:
Squamous cell carcinoma typically presents as a rough, scaly, red patch, open sore, or raised growth with a central depression, often on sun-exposed areas of the body. While it can appear as a lesion that varies in color, it is not commonly associated with a nevus that has increased in size.

Choice B reason:
Malignant melanoma is associated with changes in preexisting nevi, such as an increase in size and variations in color. It often appears as a mole that changes in color, size, or feel and may have irregular edges. The description of the lesion provided by the client is characteristic of malignant melanoma, making this the correct diagnosis.

Choice C reason:
Kaposi's sarcoma is a cancer that forms in the lining of blood and lymph vessels and typically appears as patches of abnormal tissue on the skin or mucous membranes. These lesions are usually red or purple and look similar to bruises¹. They are not typically described as nevi that increase in size or lesions that vary in color.

Choice D reason:
Basal cell carcinoma often appears as a slightly transparent bump on the skin, though it can take other forms. It usually presents as a pearly white or pink bump on white skin, or a brown or black bump on darker skin, and is most often found on sun-exposed areas. It is not typically associated with a nevus that has increased in size or an irregularly shaped lesion that varies in color.