Pigment Diseases

1- Addison's Disease

Addison’s disease (also chronic adrenal insufficiency, hypocortisolism, and hypocorticism) is a rare endocrine disorder wherein the adrenal glands produce insufficient steroid hormones (glucocorticoids and often mineralocorticoids). It is generally diagnosed via blood tests and medical imaging. Treatment involves replacing the absent hormones (oral hydrocortisone and fludrocortisone). Regular follow-up treatment and monitoring for other health problems is necessary. Addison’s disease is named after Dr. Thomas Addison.

Symptoms

The symptoms of Addison's disease develop insidiously, and it may take some time to be recognized. The most common symptoms are fatigue, lightheadedness upon standing or while upright, muscle weakness, fever, weight loss, difficulty in standing up, anxiety, nausea, vomiting, diarrhea, headache, sweating, changes in mood and personality, and joint and muscle pains. Some have marked cravings for salt or salty foods due to the urinary losses of sodium. Affected individuals may note increased tanning since adrenal insufficiency is manifested in the skin primarily by hyperpigmentation. Untreated, an Addisonian crisis can be fatal. It is a medical emergency, usually requiring hospitalization. Characteristic symptoms are:

Sudden penetrating pain in the legs, lower back or abdomen

Severe vomiting and diarrhea, resulting in dehydration

Low blood pressure

Syncope (loss of consciousness)

Hypoglycemia

Confusion, psychosis, slurred speech

Severe lethargy

Hyperkalemia

Hypercalcaemia

Convulsions

Fever

Causes:

Causes of adrenal insufficiency can be grouped by the way they cause the adrenals to produce insufficient cortisol. These are adrenal dysgenesis (the gland has not formed adequately during development), impaired steroidogenesis (the gland is present but is biochemically unable to produce cortisol) or adrenal destruction (disease processes leading to the gland being damaged).

2- Drug-induced pigmentation: Amiodarone

Long-term administration of amiodarone is associated with a blue-grey discoloration of the skin. This is more commonly seen in individuals with lighter skin tones. The discoloration may revert upon cessation of the drug. However, the skin color may not return completely to normal. Individuals taking amiodarone may become more sensitive to the harmful effects of UV-A light. Using sunblock that also blocks UV-A rays appears to prevent this side effect.

3- Melasma

Melasma (also known as "Chloasma faciei" or the mask of pregnancy when present in pregnant women) is a tan or dark skin discoloration. Although it can affect anyone, melasma is particularly common in women, especially pregnant women and those who are taking oral or patch contraceptives or hormone replacement therapy (HRT) medications. It is also prevalent in men and women of Native American descent (on the forearms) and in men and

women of German/Russian and

desc

descent

(on the face)

.

Symptoms

The symptoms of melasma are dark, irregular patches commonly found on the upper cheek, nose, lips, upper lip, and forehead. These patches often develop gradually over time. Melasma does not cause any other symptoms beyond the cosmetic discoloration.

Causes

Melasma is thought to be the stimulation of melanocytes or pigment-producing cells by the female sex hormones estrogen and progesterone to produce more melanin pigments when the skin is exposed to sun. Women with a light brown skin type who are living in regions with intense sun exposure are particularly susceptible to developing this condition.

Genetic predisposition is also a major factor in determining whether someone will develop melasma.

The incidence of melasma also increases in patients with thyroid disease. It is thought that the overproduction of melanocyte-stimulating hormone (MSH) brought on by stress can cause outbreaks of this condition. Other rare causes of melasma include allergic reaction to medications and cosmetics.

Melasma Suprarenale (Latin - above the adrenals) is a symptom of Addison's disease, particularly when caused by pressure or minor injury to the skin, as discovered by Dr. FJJ Schmidt of Rotterdam in 1859.

Diagnosis

Melasma is usually diagnosed visually or with assistance of a Wood's lamp (340 - 400 nm wavelength). Under Wood's lamp, excess melanin in the epidermis can be distinguished from that of the dermis.

Treatment

The discoloration usually disappears spontaneously over a period of several months after giving birth or stopping the oral contraceptives or hormone replacement therapy.

Treatments to hasten the fading of the discolored patches include:

Topical depigmenting agents, such as hydroquinone (HQ) either in over-the-counter (2%) or prescription (4%) strength. HQ is a chemical that inhibits tyrosinase, an enzyme involved in the production of melanin.

Tretinoin, an acid that increases skin cell (keratinocyte) turnover. This treatment cannot be used during pregnancy.

Azelaic acid (20%), thought to decrease the activity of melanocytes.

Facial peel with alpha hydroxyacids or chemical peels with glycolic acid.

Laser treatment. A Wood's lamp test should be used to determine whether the melasma is epidermal or dermal. If the melasma is dermal, Fraxel laser has been shown in studies to provide improvement in many patients[citation needed]. Intense pulsed light has also been effective in the treatment of melasma [3]. Dermal melasma is generally unresponsive to most treatments, and has only been found to lighten with products containing mandelic acid (such as Triluma cream) or Fraxel laser.

In all of these treatments the effects are gradual and a strict avoidance of sunlight is required. The use of broad-spectrum sunscreens with physical blockers, such as titanium dioxide and zinc dioxide is preferred over that with only chemical blockers. This is because UV-A, UV-B and visible lights are all capable of stimulating pigment production.

Cosmetic cover-ups can also be used to reduce the appearance of melasma.

4- Cafe Au Lait

A flat spot on the skin that is the color of coffee with milk (café au lait) in persons with light skin, or a darker appearance (café noir) than the surrounding skin in persons with dark skin. About 10% of the general population have cafe au lait spots, and they can be removed with a Yag laser. Café au lait spots are in themselves harmless, but in some cases they may be a sign of neurofibromatosis. The presence of 6 or more café au lait spots each of which is 1.5 centimeters or more in diameter is diagnostic of neurofibromatosis. Conversely, most people with neurofibromatosis who are at least 5 years old have 6 or more cafe au lait spots 1.5 centimeters or more in diameter.

Associated conditions

Neurofibromatosis type I café au lait spot

While café au lait spots do not cause any ailment themselves, having multiple spots has been linked with neurofibromatosis and the rare McCune-Albright syndrome. Specifically, having six or more café au lait spots greater than 5 mm in diameter before puberty, or greater than 15 mm in diameter after puberty, are cardinal diagnostic features of neurofibromatosis type I.

Other syndromes that may include café au lait spots:

Von Hippel – Lindau disease

Fanconi anemia

Tuberous sclerosis

Silver-Russell dwarfism

Ataxia telangiectasia

Bloom syndrome

Basal cell nevus syndrome

Gaucher disease

Chédiak-Higashi syndrome

Hunter syndrome

Marfan's syndrome

Maffucci syndrome

McCune-Albright syndrome

Peutz-Jeghers syndrome

Multiple endocrine neoplasia type 2