++
Primary immunodeficiency diseases are inherited disorders of the immune system that result in an increased susceptibility to infection and an increased morbidity and mortality. Many of these genetic immunodeficiency diseases may be associated with a variety of cutaneous abnormalities, and recognition of these clinical features may allow an early diagnosis of primary immunodeficiency. Cutaneous abnormalities may include cutaneous infections, atopic- or seborrheic-like dermatitis, macular erythemas, alopecia, poor wound healing, purpura, petechiae, telangiectasias, pigmentary dilution, cutaneous granulomas, extensive warts, angioedema, and lupus-like changes (Table 143-1). Other clinical features often include failure to thrive, visceral infection, autoimmune disorders, connective tissue/rheumatologic diseases, allergic reactions, and neoplasias.
++
++
Immunodeficiency should be suspected when patients have recurrent infections of increased duration or severity, particularly with unusual organisms. Incomplete clearing of infections, unexpected or severe complications of infection, or poor response to antibiotics may be associated.1 Affected infants often grow poorly (failure to thrive). The most common noncutaneous abnormalities are infections, diarrhea, vomiting, hepatosplenomegaly, arthritis, adenopathy or paucity of lymph nodes/tonsils, and hematologic abnormalities.
++
The classification of genetic immunodeficiency disorders includes (1) antibody deficiencies, (2) cellular deficiencies, (3) combined antibody and cellular deficiencies, (4) disorders of phagocytosis and cell killing, and (5) complement defects. The characteristic clinical signs of each group suggest that proper classification and laboratory tests may be used to confirm the diagnosis. The laboratory testing and clinical patterns of illness associated with each ...