Although patients with AD frequently possess IgE antibody specific for inhalants or food allergens, it is not generally possible to induce skin lesions or AD by intradermal injection of the suspected allergen.[28, 29] Moreover, typical lesions of AD may occur in individuals with X-linked agammaglobulinemia who have virtually no IgE.[7]. The gene discussed is IGHE; the disease is isolated agammaglobulinemia.