Human Immune System Diseases & Disorders

Disorders of the immune system may prevent gainful activity because of a serious loss of function of a single organ or body system, or lesser degrees of functional loss of two or more organs/body systems resulting in significant symptoms such as severe fatigue, fever, malaise, weight loss, joint pain and stiffness. These conditions generally evolve and persist for extended periods and may require long-term, repeated evaluation and management.

Common disorders of the immune system are:

1. Lupus (systemic lupus erythematosus)— Lupus is characterized by fever, fatigue, malaise, weight loss, multisystem involvement, and frequently, anemia, leukopenia, or thrombocytopenia.
2. Systemic vasculitis— Systemic vasculitis can occur from adverse drug reactions, chronic infections and, occasionally, malignancies, but is more often idiopathic and chronic. The diagnosis is confirmed by angiography or tissue biopsy.
3. Systemic sclerosis and scleroderma – Thickening of the skin is the clinical hallmark of these conditions. In addition to skin and blood vessels, the gastrointestinal tract, lungs, heart, kidneys, and muscle may also be involved. Joint dysfunction results primarily from soft tissue/cutaneous thickening, fibrosis, and contractures.
4. Polymyositis or dermatomyositis -This disorder is primarily an inflammation in striated muscle occurring alone or in association with other immune system disorders or malignancy. Common systems include weakness and pain and tenderness of the shoulder and/or pelvic muscles.
5. Undifferentiated connective tissue disorders— Persons with undifferentiated connective tissue disorders may display clinical and immunologic features of several connective tissue disorders, but do not satisfy the specific criteria for diagnosis of a specific condition. For example, the individual may have features of both rheumatoid arthritis and scleroderma. The correct diagnosis is important for assessment of prognosis.
6. Inflammatory arthritis— Inflammatory arthritis includes an array of disorders that differ in cause, course, and outcome. Inflammation of major joints may be the dominant problem causing difficulties with ambulation or fine and gross movements, or the arthritis may involve other joints or cause less restriction of ambulation or other movements but be complicated by extra-articular features that result in serious functional deficit.
7. Human immunodeficiency virus (HIV)— HIV infection is caused by a specific retrovirus and may be characterized by susceptibility to one or more opportunistic diseases, cancers, or other conditions. Evidence of HIV diagnosis may include documentation of HIV infection by appropriate laboratory tests or may be determined by other documentation consistent with the prevailing state of medical knowledge and clinical practice.

The finding of disability for persons with HIV is based on the effects of treatment and on the individual’s ability to function. Important factors used in evaluating disability of individuals with HIV include symptoms,
such as fatigue and pain; characteristics of the illness, such as the frequency and duration of manifestations or periods of exacerbation and remission; and the functional impact of treatment, including the side effects of medication.

The diagnosis of an immune system disorder is established by medical history, physical examination, appropriate laboratory studies and imaging, and, occasionally, tissue biopsy. A disability diagnosis requires that a person show active disease for at least three months, despite prescribed treatment with the expectation that the disease will remain active for 12 months.

In addition to the limitations caused by the specific disorder, the chronic adverse effects of treatment may result in functional loss and be considered in the determination of disability.

This summary cannot cover every medical condition and/or functional loss. The Social Security Administration offers more detail on its website.