A congenitally determined tissue abnormality (or birthmark). In the SKIN, naevi composed of tiny blood vessels are most common, but a MOLE is a MELANOCYTE naevus, and warty, streaked and linear naevi of the epidermis occasionally occur.
Also known as ‘salmon patch’ or ‘stork marks’. About one-third of white children are born with macular pink areas of ERYTHEMA on the nape, brow or eyelids which usually disappear after a few months; patches on the nape may persist.
Also known as ‘port-wine stain’, it is usually on one side of the face, and may be extensive. It tends to darken with age and is permanent. Laser treatment is often effective.
(cavernous haemangioma) is usually not visible at birth but appears within a few weeks and grows rapidly, reaching a peak in size after 6–12 months, when the lobulated red nodule may resemble a ripe strawberry. Untreated, it disappears spontaneously over several years. It may occur anywhere and may be very troublesome near an eye or on the ‘nappy’ area. If possible it should be left alone, but where it is causing problems other than cosmetic, it may be treated with steroids, interferon or laser therapy.
is due to a dilated ARTERIOLE causing a minute red papule (‘pimple’) in the skin, the small branching vessels resembling spider legs. A few spider naevi are common in young people, but multiple naevi are common in pregnancy and may also be a warning sign of chronic liver disease.