A patient is especially worried about an area of skin on her feet that has turned white.
The health care provider has told her that her condition is vitiligo.
The nurse explains to her that vitiligo is:

Choice A rationale

Vitiligo is a condition caused by the destruction or malfunction of melanocytes, the cells responsible for producing melanin pigment. This leads to the development of white patches on the skin, as melanin is absent in these areas. Vitiligo is an autoimmune condition and can affect any part of the body, including the skin, hair, and mucous membranes.

Choice B rationale

Excess apocrine glands in the feet are not related to vitiligo. Apocrine glands are sweat glands found primarily in the underarm and genital areas and are responsible for the secretion of a thick, odorless fluid. Their overactivity does not result in the white patches seen in vitiligo.

Choice C rationale

Impetigo is a bacterial skin infection characterized by red sores, blisters, and crusting. It is not related to vitiligo and does not cause depigmentation. Impetigo is treated with antibiotics, whereas vitiligo requires different management strategies to address the loss of pigment.

Choice D rationale

Vitiligo is not caused by an excess of melanin pigment. Rather, it is the result of melanin loss or the absence of melanocytes in certain areas of the skin, leading to the characteristic white patches.

Choice A rationale

An elliptical chest describes the typical shape of a healthy chest with a lateral dimension greater than the anteroposterior dimension. This shape allows for normal expansion and contraction of the lungs during breathing. An elliptical chest does not indicate any deformity or abnormality in the sternum or costal cartilage.

Choice B rationale

Pectus excavatum, also known as funnel chest, is a congenital deformity where the sternum and costal cartilage are sunken inward, creating a concave appearance of the chest. This condition can range in severity and may affect respiratory function and exercise tolerance in some individuals. Surgical correction may be considered for severe cases.

Choice C rationale

A standard chest describes a chest without any deformities or abnormalities, typically with a normal elliptical shape. This term does not denote any specific condition or configuration and implies a healthy, non-deformed chest.

Choice D rationale

Barrel chest is characterized by an increased anteroposterior diameter of the chest, giving it a round or barrel-like appearance. This condition is often seen in individuals with chronic obstructive pulmonary disease (COPD) or emphysema, where the lungs are chronically overinflated, causing the chest to expand and lose its normal shape.