This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Autoimmune skin disorders, Subject name: Dental
Omenn syndrome is a form of 
Select and explain. 
A. Squamous cell carcinoma, B. Chronic mucocutaneous candidiasis, C. IgA deficiency, D. Severe combined immunodeficiency
D: Severe combined immunodeficiency
Answer: D: Severe combined immunodeficiency 
Explanation: Omenn syndrome is an autosomal recessive form of severe combined immunodeficiency (SCID) characterized by erythroderma (skin redness), desquamation (peeling skin), alopecia (hair loss), chronic diarrhoea, failure to thrive, lymphadenopathy (enlarged lymph nodes), eosinophilia, hepatosplenomegaly, and elevated serum IgE levels. Ref Harrison 20th edition pg 1234