Occurence of Discoid Eczema

Discoid eczema, also called nummular eczema, varicose eczema, or gravitational eczema is usually found in adults and appears suddenly as a few coin shaped areas of red skin normally on the trunk or lower legs. This rash may look similar to ringworm. These areas become itchy and can weep fluid. Discoid eczema is often treated successfully with moisturizers. It can be considered as an adult form of atopic eczema. Discoid eczema may be complicated by a bacterial infection, which causes weeping and crusting.

Discoid eczema can affect any part of the body particularly the lower leg. It most commonly appears on the arms, back, buttocks, and lower legs and may be crusted, scaling, and extremely itchy. Neurodermatitis most commonly appears as scaly patches of skin on the head, lower legs, wrists, or forearms caused by a localized itch that becomes intensely irritated when scratched. Minor skin injury such as an insect bite or a burn may start it off.

Discoid eczema may be termed varicose eczema when it runs along the leg veins and results in gravitational eczema. One or many patches appear, and may persist for weeks or months. The patches can be several centimeters across, or as small as two millimeters. The skin between the patches is usually normal, but may be dry and irritable. Discoid eczema may be extremely itchy, or barely noticeable. When the patches clear, they may leave marks for some weeks or months, which are darker or sometimes paler than the normal skin tone. Discoid eczema does not run in families, and unlike atopic dermatitis, it is not associated with asthma. It does not result from food allergy. Discoid eczema is not infectious to other people, although bacteria sometimes secondarily infect it.

As this type of eczema often starts off as a minor skin injury, protect all of your skin carefully. If the hands are affected, use gloves and tools to make sure friction, detergents, solvents, other chemicals or excessive water do not irritate the skin.

An eruption may begin with one or numerous round red plaques with tiny overlying blisters. The plaques often enlarge to several centimeters with clearly marked edges, and overlying scales may be prominent. Swelling and oozing occur in newer lesions and itching can be mild to severe.

This type of eczema shows as discrete coin-shaped patches of eczema on the limbs. It can occur:

  • on otherwise normal skin
  • with generally dry skin
  • with atopic eczema

Discoid eczema can affect all age groups and both sexes, but is usually associated with middle-aged or older men.

Causes of Discoid Eczema

The cause of discoid eczema is not known, but it usually occurs in cold weather and is most common in people who have dry skin. Typical aggravating factors in discoid eczema include:

  • Hot weather
  • Stress
  • Fabric softeners
  • Allergies
  • Soaps and detergents
  • Wearing wool clothing
  • Bathing more than once a day
  • Minor skin injury such as an insect bite or a burn may instigate an episode
  • Dry skin in the winter months can cause dry non-itchy resulting in round patches.

In younger people, discoid eczema tends to be seen in conjunction with atopic eczema. In adults it is said to be possibly associated with stress, local irritation of the skin, and drinking too much alcohol.

Symptoms of Discoid Eczema

Discoid eczema can affect any part of the body with particular emphasis on the lower leg. One or many patches appear, and may persist for weeks or months. The majority of patches are round or oval, hence the name 'discoid' or 'nummular' dermatitis, which refers to their disc or coin shape. They can be several centimeters across, or as small as two millimeters.

These well-defined patches are pink, red, or brown. They have a dry cracked surface or a bumpy, blistered or crusted surface. Discoid eczema may be extremely itchy, or scarcely noticeable. The skin between the patches is usually normal, but may be dry and irritable.

The patches may clear up without leaving a sign. However, in darker skin, marks may persist for months. These may be dark brown (post inflammatory hyper pigmentation) or paler than surrounding skin (post inflammatory hypo pigmentation).

In most cases, the appearance of discoid eczema is quite characteristic. Bacterial swabs may reveal Staphylococcus aureus colonisation or infection. Scrapings are commonly taken for mycology, as discoid eczema can look very similar to tinea corporis (ringworm infection). Sometimes patch testing is arranged to see whether there could be a contact allergy responsible for the dermatitis. In most cases no specific allergy can be found.

The affected areas have a well-defined edge and are red. On top there are often small blisters, scales or crusts. This often reflects the fact that they are infected with bacteria. Because of their well-defined margins, lesions of discoid eczema can be confused for fungal infections of the skin (ringworm) or for contact eczema.

Usually the pattern of skin lesions (affected areas) on the limbs is symmetrical. The lesions are very itchy, so thickening of the skin (lichenification) is common.

Controlling Discoid Eczema

Methods of controlling discoid eczema include the following:

  • Protecting the skin from injury. As this type of dermatitis often starts off as minor skin injuries, protect all of your skin carefully. If the hands are affected, use gloves and tools to make sure friction, detergents, solvents, other chemicals or excessive water does not irritate the skin.
  • Using moisturizers such as bath oils, soap substitutes and moisturizing creams. These can be applied to the eczema as frequently as required to relieve itching, scaling and dryness. Moisturizers should also be used on the unaffected skin to reduce dryness. It may be necessary to try several different products to find one that suits. Many people find one or more of the following helpful: aqueous cream, glycerine and cetomacrogol cream, white soft paraffin/liquid paraffin mixed, wool fat lotions.
  • Taking antibiotics (most often flucloxacillin) is important if the dermatitis is weeping, sticky, or crusted. Sometimes nummular dermatitis clears completely on oral antibiotics, only to recur when they are discontinued.
  • Using antihistamines may reduce the itching and can be particularly helpful at nighttime. They do not clear the dermatitis. Newer non-sedating antihistamines appear less useful for this condition, possibly because part of the effect of the conventional type is making the person sleepy.
  • Using ultraviolet light treatment several times weekly can help in some cases or cause further irritation in others. It may take several months to control the eczema, but is worthwhile for more severe cases.
  • Apply Eczema-Ltd III patented topical skin conditioner disks to the affected skin.

Nummular/discoid eczema can usually be controlled with the above measures, although it has a tendency to recur when the treatment has been stopped. Make sure the skin is kept well moisturized, and protected from injury. Eventually, the eczema should clear up completely. However, discoid eczema tends to be more difficult to get rid of than atopic eczema. Because infection is common in discoid eczema, antibiotic treatment (topical or by mouth if more severe) may be required if the eczema proves difficult to control.