Polymorphous light eruption Health Dictionary

Eruption, or rash, means an outbreak, in a scattered form, upon the surface of the skin. The skin is usually raised and red, or it may be covered with scales, or crusts, or vesicles containing ?uid. Eruptions di?er in appearance: for example, the eruption of MEASLES is always distinguishable from that of CHICKENPOX. But the same disease may also produce di?erent eruptions in di?erent people; or in the same person in di?erent states of health; or even on di?erent parts of the body at one time.

Eruptions may be acute or chronic. Most of the acute eruptions belong to the exanthemata (see EXANTHEM): that is, they are bright in col-our and burst out suddenly like a ?ower. These are the eruptions of SCARLET FEVER, measles, German measles (see RUBELLA), SMALLPOX and chickenpox. In general, the severity of these diseases can be measured by the amount of eruption. Some eruptions are very transitory, like nettle-rash, appearing and vanishing again in the course of a few hours. (See also SKIN, DISEASES OF.)... eruption

Creeping eruption is a skin condition caused by the invasion of the skin by the larvae of various species of nematode worms. It owes its name to the fact that as the larva moves through and along the skin it leaves behind it a long creeping thin red line. (See STRONGYLOIDIASIS.)... creeping eruption

(American) A lighthearted woman Lite, Lyte... light

Pupillary constriction in the EYE in response to light. The direct light re?ex involves pupillary constriction in the eye into which a light is shone; the consensual light re?ex is the pupillary constriction that occurs in the other eye. The a?erent or inward pathway of the re?ex is via the optic nerve, and the e?erent or outward pathway is via the occulomotor nerve.... light reflex

A mechanical trap which use a combination of light and/or carbon dioxide to attract and trap adult mosquitoes, e.g. Centres for Disease Control and Prevention (CDC) Light Trap.... light traps

Reactions on the skin due to drug allergy. Symptoms may manifest as urticaria or exanthemata. Aspirin may produce urticaria. Mercury, arsenic, gold, mepacrine and others manifest in their own distinctive rash or vesicles.

Treatment: same as for NETTLE RASH. ... drug eruptions

The process by which developing teeth move upwards through the jawbone and break through the gum to project into the mouth.

Deciduous teeth (milk teeth) usually begin to appear at about 6 months of age. All 20 deciduous teeth have usually erupted by 3 years (see teething).

Permanent teeth (also known as secondary teeth) usually begin to appear at about 6 years of age. The first permanent molars erupt towards the back of the mouth and appear in addition to the deciduous teeth. The eruption of permanent teeth nearer the front of the mouth is preceded by reabsorption of the roots of the deciduous teeth, which become loose and detach. Eventually, permanent teeth replace all the deciduous ones. Wisdom teeth (the backmost, or 3rd, molars) usually erupt between ages 17 and 21, but, in some people, they never appear.... eruption of teeth

Invisible light from the part of the electromagnetic spectrum immediately beyond the violet end of the visible light spectrum. Long wavelength ultraviolet light is termed , intermediate , and short.

Ultraviolet light occurs in sunlight, but much of it is absorbed by the ozone layer. The ultraviolet light (mainly ) that reaches the earth’s surface causes the tanning effects of sunlight and the production of vitamin D in the skin. It can have harmful effects, such as skin cancer (see sunlight, adverse effects of).

Ultraviolet light is sometimes used in phototherapy.

A mercury-vapour lamp (Wood’s light) can also produce ultraviolet light.

This is used to diagnose skin conditions such as tinea because it causes the infected area to fluoresce.... ultraviolet light

reflex changes in the eye to enable vision either in normal light after being in darkness or in very bright light after being in normal light. The pupil contracts (see pupillary reflex) and the pigment in the *rods is bleached. Compare dark adaptation.... light adaptation

see pupillary reflex.... light reflex

(PEP) intensely itchy papules and weals on the abdomen (except the umbilicus), upper limbs, and buttocks, usually within the *striae gravidarum; it is also known as PUPPP (pruritic urticarial papules and plaques of pregnancy). It occurs in 1 in 250 first pregnancies late in the third trimester. This condition is harmless to mother and baby, but can be very annoying. It lasts an average of 6 weeks and resolves spontaneously 1–2 weeks after delivery. The most severe itching normally lasts for no more than a week.... polymorphic eruption of pregnancy

ultraviolet light filtered through a nickel oxide prism, which causes fluorescence in skin and hair affected by some fungal and bacterial infections and is therefore useful in diagnosis. For example, *erythrasma fluoresces coral pink, while scalp ringworm caused by Microsporum species fluoresces green. [R. W. Wood (1868–1955), US physician]... wood’s light