during the period from July 2008 till June 2009. They were 36 males and 18 females, and their age ranged from 20 to 65 years. The control group consisted of 40 age- and sex-matched generally healthy subjects, 26 males and 14 females, with no scalp lesions in their personal history or on clinical examination. All subjects of the study (patients and controls) were subjected to: full history taking and dermatological examination including: search for possible associations with AA such as atopic dermatitis and vitiligo and clinical assessment of AA lesions including: number of the lesions, site and size of the lesions, and classification according to clinical severity into: LAA, AT, and AU. All subjects of the study were subjected to: stool analysis to exclude parasitic infestation, complete bloodintracellular cytoplasmic spaces. It exists as a 32 kDa homodimer and is present in the cytoplasm and nucleus of every cell type examined ([@b103-ajas-28-5-730]). The second member of the family (SOD2) has manganese (Mn) as a cofactor and therefore called Mn-SOD. It was shown to be a 96 kDa homotetramer and located exclusively in the mitochondrial matrix, a prime site of superoxide radical production ([@b38-ajas-28-5-730]). Mn-SOD is inducible enzyme and its activity is affected by cytokines and oxidative stress. In 1982, a third SOD isozyme was discovered by Marklund and co-workers and called extracellular superoxide dismutase (EC-SOD), due to its exclusive extracellular location. The EC-SOD is a glycoprotein with a molecular weight of 135,000 kDa with high affinity for heparin. The expression pattern of EC-SOD is highly restricted