The clinical presentation of oral lesions in immunosuppressed children is highly variable. In some cases, it is the oral manifestations that result in the discovery an underlying disease responsible for the immunosuppression. Immunosuppression/ immune deficiency can either be primary or acquired. The World Health Organization recognizes more than 100 primary immune deficiency diseases. Examples include DiGeorge syndrome, complement deficiencies, X-linked agammaglobulinemia (Bruton’s) disease, immunoglobulin heavy chain deficiency, selective IgA deficiency, transient hypo-gammaglobulinemia of infancy, phagocytic disorders, severe congenital neutropenia (Kostmann syndrome), cyclic neutropenia, leukocyte adhesion defects, Chediak–Higashi syndrome, etc. Examples of acquired immunosuppression include HIV/AIDs and medication-induced immunosuppression seen in transplant patients as well as children undergoing chemotherapy.

Epidemiology of primary immune deficiency diseases varies depending on the geographic region, ethnic factors, race, and gender. In the United States it is estimated that 1:2000 children has a primary immune deficiency disease.

Children with immune deficiency are more susceptible to opportunistic fungal, viral, and bacterial infections. Often times, these infections can have a presentation that is atypical and severe. In addition, the oral lesions can take longer to resolve. Early detection and aggressive treatment of oral soft tissue infection is essential in children with suppressed immune system or immune deficiency disorder. Cultures can be utilized in many cases to help identify the infectious agent, thus ensuring appropriate treatment.