Damage to the small hormone-producing glands on top of each kidney (adrenal glands) results in a third major feature of APECED, adrenal gland insufficiency (autoimmune Addison disease). Reduced hormone production by the adrenal glands leads to signs and symptoms that can include fatigue, muscle weakness, loss of appetite, weight loss, low blood pressure, and changes in skin coloring. Other endocrine problems that can occur in APECED include type 1 diabetes resulting from impaired production of the hormone insulin; a shortage of growth hormone leading to short stature; problems affecting the internal reproductive organs (ovaries or testes) that can cause inability to conceive children (infertility); and dysfunction of the thyroid gland (a butterfly-shaped tissue in the lower neck), which can result in many symptoms including weight gain and fatigue.

Autoimmune problems affecting non-endocrine tissues can lead to a variety of additional signs and symptoms in people with APECED. These features occur more often in North American populations than in European populations. Rashes that resemble hives (urticarial eruptions) are common and often occur in infancy and early childhood. Other early signs and symptoms may include thin enamel on the teeth (enamel hypoplasia) and chronic diarrhea or constipation associated with difficulty in absorbing nutrients from food. Additional features that occur in people with APECED, many of which can lead to permanent organ and tissue damage if left untreated, include stomach irritation (gastritis), liver inflammation (hepatitis), lung irritation (pneumonitis), dry mouth and dry eyes (Sjogren-like syndrome), inflammation of the eyes (keratitis), kidney problems (nephritis), vitamin B12 deficiency, hair loss (alopecia), loss of skin color in blotches (vitiligo), high blood pressure (hypertension), or a small (atrophic) or absent spleen (asplenia).

Other features of APECED result from the body's immune system attacking the network of hormone-producing glands (the endocrine system). The second characteristic feature of the disorder is hypoparathyroidism, which is a malfunction of the parathyroid glands. These glands secrete a hormone that regulates the body's use of calcium and phosphorus. Damage to the parathyroid glands leads to reduced parathyroid hormone production (hypoparathyroidism). Hypoparathyroidism can cause a tingling sensation in the lips, fingers, and toes; muscle pain and cramping; weakness; and fatigue. Serious effects of hypoparathyroidism, such spasms of the voicebox (larynx) leading to breathing problems and seizures, can be life-threatening.

CMC is a tendency to develop infections of the skin, the nails, and the moist lining of body cavities (mucous membranes) caused by a type of fungus called Candida. These infections, which are commonly known as yeast infections, are chronic, which means they recur and can last a long time. CMC is usually the first of the three characteristic features of APECED to become apparent in people with this disorder. Almost all affected individuals develop infections of the oral cavity (known as thrush). Infections of the tube that carries food from the mouth to the stomach (the esophagus) are also common, while the skin and nails are affected less often. In women, vaginal infections frequently occur.

In most cases, the signs and symptoms of APECED begin in childhood or adolescence. This condition commonly involves three characteristic features: chronic mucocutaneous candidiasis (CMC), hypoparathyroidism, and adrenal gland insufficiency. Affected individuals typically have at least two of these features, and many have all three.

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is an inherited condition that affects many of the body's organs. It is one of many autoimmune diseases, which are disorders that occur when the immune system malfunctions and attacks the body's own tissues and organs by mistake. [from MedlinePlus Genetics]