Chronic inflammation of the skin with increased sensitivity to irritants, such as soaps, certain fabrics, or changes in temperature and humidity is called:

Alpha hemolysis is characterized by partial lysis of red blood cells on blood agar, leading to a greenish or brownish discoloration around bacterial colonies rather than a clear zone. This occurs because the bacteria produce hemolysins that oxidize hemoglobin to methemoglobin, causing the greenish hue, but do not completely lyse the red blood cells. In contrast, beta hemolysis results in complete destruction of red blood cells and a clear zone surrounding the colonies. Therefore, alpha hemolysis produces incomplete hemolysis with color change rather than full destruction and clearing of the agar.

A. Western European is incorrect because sickle cell anemia is rare among individuals of Western European descent. While carriers exist, the prevalence is much lower than in populations of African ancestry.

B. Native American is incorrect because sickle cell anemia is uncommon in Native American populations. Other hemoglobinopathies, like thalassemia, may be more prevalent in specific indigenous groups.

C. African is correct because sickle cell anemia is caused by a recessive mutation in the HBB gene, which affects the beta chain of hemoglobin. This mutation leads to the production of abnormal hemoglobin S, causing red blood cells to adopt a sickle shape under low oxygen conditions. Sickle-shaped cells are rigid, sticky, and prone to hemolysis, leading to anemia, vaso-occlusive crises, and organ damage. The gene is more commonly found in individuals of African descent, as heterozygosity (carriers) provides some protection against malaria, which historically explains the high prevalence in Africa.

D. Asian is incorrect because sickle cell anemia is relatively rare in Asian populations. Other hemoglobin disorders, such as thalassemia, are more common in Southeast Asian and Mediterranean populations.