Effective prevention and therapy of MAC has the potential to contribute substantially to improved quality of life and duration of survival for HIV-infected persons. Pathophysiology
MAC is the most commonly found form of NTM.Immunodeficiency is not a requirement for MAI.MAC usually affects patients with abnormal lungs or bronchi. However, Jerome Reich and Richard Johnson describe a series of six patients with MAC infection of the right middle lobe or lingula who did not have any predisposing lung disorders.The right middle lobe and lingula of the lungs are served by bronchi that are oriented downward when a person is in the upright position. As a result, these areas of the lung may be more dependent upon vigorous voluntary expectoration (cough) for clearance of bacteria and secretions.Since the six patients in their retrospective case series were older females, Reich and Johnson proposed that patients without a vigorous cough may develop right middle lobe or left lingular infection with MAC. They proposed this syndrome be named Lady Windermere syndrome, after the character Lady Windermere in Oscar Wildes play Lady Windermeres Fan. However, little research has confirmed this speculative cause. Diagnosis
Diagnosis can be achieved through blood cultures or cultures of other bodily fluids such as sputum. Bone marrow culture can often yield an earlier diagnosis but is usually avoided as an initial diagnostic step because of its invasiveness. Many people will have anemia and neutropenia if the bone marrow is involved.
By region, it affects about 1 in 370 in India, 1 in 20,000 in Japan, 1 in 250,000 people in the United States and 1 in 430,000 in Europe. It occurs equally commonly in males and females. Xeroderma pigmentosum was first described in the 1870s by Moritz Kaposi. In 1882, Kaposi coined the term xeroderma pigmentosum for the condition, referring to its characteristic dry, pigmented skin. Individuals with the disease have been referred to as "children of the night" or "moon children". Signs and symptoms
Signs and symptoms of xeroderma pigmentosum may include:
Severe sunburn when exposed to only small amounts of sunlight. These often occur during a childs first exposure to sunlight. Development of many freckles at an early age
Rough-surfaced growths (solar keratoses), and skin cancers
Eyes that are painfully sensitive to the sun and may easily become irritated, bloodshot and clouded
Blistering or freckling on minimum sun exposure
Telangiectasia (spider veins)
Limited growth of hair on chest and legs
Scaly skin
Xeroderma (dry skin)
Irregular dark spots on the skin
Corneal ulcerations

Genetics
One of the most frequent defects in xeroderma pigmentosum is an autosomal recessive genetic defect in which nucleotide excision repair (NER) enzymes are mutated, leading to a reduction in or elimination of NER. If left unchecked, damage caused by ultraviolet light can cause mutations in individual cells DNA. The causes of the neurological abnormalities are poorly understood and are not connected with exposure to ultraviolet light.