Isotretinoin Health Dictionary

A common skin condition starting after puberty, and which may persist for many years. It involves plugged pores (blackheads and whiteheads), pimples and deeper nodules on the face, neck, trunk and even the upper arms. It arises from pilosebaceous glands (relating to hair follicles and associated SEBACEOUS GLANDS). SEBUM production is increased and bacterial proliferation causes in?ammation with PAPULE and PUSTULE formation. Plugs of sebum and epidermal cells form blackheads (comedones); the colour is not due to dirt but to dried oil and shed skin cells in the hair-follicle openings.

Treatment Twice-daily washing with a salicylic-acid cleanser can help remove the pore-blocking debris, as can daily shampooing. Use only oil-free cosmetics and hide blackheads with a ?esh-tinted acne lotion containing benzoyl peroxide, acid or sulphur. Never squeeze blackheads, however tempting; ask a skin specialist how to do this properly. Other treatments include microdermabrasion, and the antibiotic lotions erythromycin and clindamycin may be e?ective. Tretinoin and adapilene can be used on the skin but are not permitted in pregnancy and may cause problems such as hypersensitivity to sunlight, so medical advice is essential. In resistant cases, long-term suppressive oral therapy with one of the TETRACYCLINES or with ERYTHROMYCIN may be necessary. In females a combined oestrogenantiandrogen ‘pill’ is an alternative. Severe resistant acne can be cleared by a 16- to 24week course of oral isotretinoin, but this drug is teratogenic (see TERATOGENESIS) and can cause many side-effects including depression, so its use requires specialist supervision.

See www.skincarephysicians.com/acnenet/... acne

An infectious skin disease caused usually by Staphylococcus aureus and less often by Streptococcus pyogenes. The itching rash is seen especially on the face but may spread widely. Vesicles and pustules erupt and dry to form yellow-brown scabs. Untreated, the condition may last for weeks. In very young infants, large blisters may form (bullous impetigo).

Treatment Crusts should be gently removed with SALINE. Mild cases respond to frequent application of mupiricin or NEOMYCIN/BACITRACIN ointment; more severe cases should be treated orally or, sometimes, intravenously with FLUCLOXACILLIN or one of the CEPHALOSPORINS. If the patient is allergic to penicillin, ERYTHROMYCIN can be used.

For severe, intractable cases, an oral retinoid drug called isotretinoin (commercially produced as Roaccutane®) can be used. It is given systemically but treatment must be supervised by a consultant dermatologist as serious side-effects, including possible psychiatric disturbance, can occur. The drug is also teratogenic (see TERATOGENESIS), so women who are, or who may become, pregnant must not take isotretinoin. It acts mainly by suppressing SEBUM production in the sebaceous glands and can be very e?ective. Recurrent bouts of impetigo should raise suspicion of underlying SCABIES or head lice. Bactericidal soaps and instilling an antibiotic into the nostrils may also help.... impetigo

Abnormalities that are obvious at birth or detectable early in infancy. Also called congenital defects, they encompass both minor abnormalities, such as birthmarks, and serious disorders such as spina bifida.

Causes include chromosomal abnormalities, genetic defects, drugs taken during pregnancy, exposure to radiation, and infections. In some cases, the cause of a defect is unknown. Defects that are due to chromosomal abnormalities include Down’s syndrome. Some defects, such as achondroplasia and albinism, are usually inherited from 1 or both parents (see gene; genetic disorders). Certain drugs and chemicals (called teratogens) can damage the fetus if the mother takes or is exposed to them during early pregnancy. Teratogenic drugs include thalidomide (now rarely prescribed) and isotretinoin, which is used in the treatment of severe acne. Alcohol can affect the development of the brain and face (see fetal alcohol syndrome).

Irradiation of the embryo in early pregnancy can cause abnormalities. Very small doses of radiation increase the child’s risk of developing leukaemia later in life (see radiation hazards).

Certain illnesses, such as rubella (German measles) and toxoplasmosis, can cause birth defects if they are contracted during pregnancy.

Brain and spinal cord abnormalities, such as spina bifida and hydrocephalus, and congenital heart disorders (see heart disease, congenital) result from interference with the development of particular groups of cells. Other common defects include cleft lip and palate.

Ultrasound scanning and blood tests during pregnancy can identify women at high risk of having a baby with a birth defect. Further tests such as chorionic villus sampling, amniocentesis, or fetoscopy may then be carried out.... birth defects

n. a chronic inflammatory disease of the face in which the skin becomes abnormally flushed. At times it becomes pustular and there may be an associated *keratitis. The disease occurs in both sexes and at all ages but is most common in women in their thirties; the cause is unknown. Treatment is with topical metronidazole; oral tetracyclines, erythromycin, or isotretinoin; or pulsed dye laser.... rosacea

n. any one of a group of drugs derived from vitamin A. They bind to one or more of six specific receptors that are found on many cells. On the skin they act to cause drying and peeling and a reduction in oil (sebum) production. These effects can be useful in the treatment of severe *acne, *psoriasis, *ichthyosis, and other skin disorders. Retinoids include *isotretinoin, *tretinoin, acitretin, tazarotene, and alitretinoin, which is particularly effective for hyperkeratotic hand eczema. Possible side-effects, which may be serious, include severe fetal abnormalities (if taken by pregnant women), toxic effects on babies (if taken by breastfeeding mothers), liver and kidney damage, excessive drying, redness and itching of the skin, and muscle pain and stiffness.... retinoid