Eczema is a form of dermatitis, or inflammation
of the upper layers of the skin.
The term "eczema" is broadly applied
to a range of persistent skin conditions.
These include dryness and recurring skin rashes characterized
by redness, skin edema, itching and dryness, with possible crusting, flaking, blistering, cracking, oozing, or bleeding.
Areas of temporary skin discoloration are sometimes due to healed lesions, although scarring is rare.
Types of common eczemas- Atopic eczema (aka infantile e., flexural e., atopic dermatitis) is believed
to have a hereditary component, and often runs in families whose members also have hay fever and asthma. Itchy rash is particularly
noticeable on face and scalp, neck, inside of elbows, behind knees, and buttocks. Experts are urging doctors to be more vigilant
in weeding out cases that are in actuality irritant contact dermatitis. It is very common in developed countries, and rising.
(L20)
- Contact dermatitis is of two types: allergic (resulting from a delayed
reaction to some allergen, such as poison ivy or nickel), and irritant (resulting from direct reaction to a solvent, for example).
Some substances act both as allergen and irritant (e.g. wet cement). Other substances cause a problem after sunlight exposure,
bringing on phototoxic dermatitis. About three quarters of cases of contact eczema are of the irritant type, which is the
most common occupational skin disease. Contact eczema is curable provided the offending substance can be avoided, and its
traces removed from one’s environment. (L23; L24; L56.1; L56.0)
- Xerotic eczema (aka asteatotic e., e. craquele or craquelatum, winter itch, pruritus hiemalis)
is dry skin that becomes so serious it turns into eczema. It worsens in dry winter weather, and limbs and trunk are most often
affected. The itchy, tender skin resembles a dry, cracked, river bed. This disorder is very common among the older population.
Ichthyosis is a related disorder. (L85.3; L85.0)
- Seborrhoeic dermatitis (aka cradle cap
in infants, dandruff) causes dry or greasy scaling of the scalp and eyebrows. Scaly pimples and red patches sometimes appear
in various adjacent places. In newborns it causes a thick, yellow crusty scalp rash called cradle cap which seems related
to lack of biotin, and is often curable. (L21; L21.0)
Less common eczemas- Dyshidrosis (aka dyshidrotic
e., pompholyx, vesicular palmoplantar dermatitis, housewife’s eczema) only occurs on palms, soles, and sides of fingers
and toes. Tiny opaque bumps called vesicles, thickening, and cracks are accompanied by itching which gets worse at night.
A common type of hand eczema, it worsens in warm weather. (L30.1)
- Discoid eczema (aka nummular e.,
exudative e., microbial e.) is characterized by round spots of oozing or dry rash, with clear boundaries, often on lower legs.
It is usually worse in winter. Cause is unknown, and the condition tends to come and go. (L30.0)
- Venous eczema
(aka gravitational e., stasis dermatitis, varicose e.) occurs in people with impaired circulation, varicose veins and edema,
and is particularly common in the ankle area of people over 50. There is redness, scaling, darkening of the skin and itching.
The disorder predisposes to leg ulcers. (I83.1)
- Dermatitis herpetiformis (aka Duhring’s Disease)
causes intensely itchy and typically symmetrical rash on arms, thighs, knees, and back. It is directly related to celiac disease,
and can often be put into remission with appropriate diet. (L13.0)
- Neurodermatitis (aka lichen simplex
chronicus, localized scratch dermatitis) is an itchy area of thickened, pigmented eczema patch that results from habitual
rubbing and scratching. Usually there is only one spot. Often curable through behavior modification and anti-inflammatory
medication. Prurigo nodularis is a related disorder showing multiple lumps. Autoeczematization (aka id reaction,
autosensitization) is an eczematous reaction to an infection with parasites, fungi, bacteria or viruses. It is completely
curable with the clearance of the original infection that caused it. The appearance varies depending on the cause. It always
occurs some distance away from the original infection
- There are also eczemas overlaid by viral infections
(e. herpeticum, e. vaccinatum), and eczemas resulting from underlying disease (e.g. lymphoma). Eczemas originating from ingestion
of medications, foods, and chemicals, have not yet been clearly systematized. Other rare eczematous disorders exist in addition
to those listed here.
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