Dermatitis

Types of Dermatitis

There are different types of dermatitis, and the condition can have many causes and appear
in many forms:

Allergic Contact Dermatitis
Atopic Dermatitis
Hand Dermatitis
Seborrhoeic Dermatitis
Perioral Dermatitis

Allergic Contact Dermatitis

Allergic Contact Dermatitis is an itchy skin condition caused by an allergic reaction to material in contact with the skin. It is distinct from Irritant Contact Dermatitis, in which a similar skin condition is caused by excessive contact
with irritants.
 

Causes

Allergy is the term given to a reaction by a small number of people to a substance (known as the allergen), which is harmless to those who are not allergic to it. Only small quantities of allergen are necessary to induce the reaction. Contact allergy occurs predominantly from the allergen on the skin rather than from internal sources or food. The first contact does not necessarily result in allergy; often the person has been able to touch the material for many years without adverse reaction.

Contact Dermatitis is generally confined to the site of contact with the allergen, although severe cases may extend outside the contact area or it may become generalised. Sometimes the allergen is transmitted from the fingers so unexpected sites can be affected e.g. the eyelids and genitals. Dermatitis is unlikely to be due to a specific allergen if the area of skin most in contact with that allergen is unaffected.
 

Some typical examples of Allergic Contact Dermatitis include:

• An eczema of the wrist underlying a watch strap due to a contact allergy to nickel.
• An eczema of the lower leg when ankle strapping has been removed due to contact allergy to colophony in the adhesive plaster.
• Hand Dermatitis caused by an anti-oxidant chemical used in the manufacture of rubber gloves.
• Itchy red face due to contact allergy with a preservative in a moisturiser.
• Contact allergy arises only after the skin has been exposed to ultraviolet light.

It is important to recognise how you are in contact with the responsible substance so that, where possible, you can avoid it.

• Find out precisely what you are allergic to by having comprehensive patch tests.
• Identify where the allergen is found.
• Carefully study your environment to locate the allergen. Note: many chemicals have several names, and cross-reactions to similar chemicals with different names are common.
   

Treatment

• Emollient creams (mositurisers).
• Topical steroids (cortisone creams).
• Topical or oral antibiotics for secondary infection.
• Oral steroids, usually short courses, for severe cases.
• Phototherapy (UV light).

Atopic Dermatitis

Atopic Dermatitis is more commonly referred to as eczema. It appears as an itchy rash mostly on people with sensitive skin.

Atopic Dermatitis is quite common in children affecting as many as 1 in 7. In most cases it disappears towards adolescence and adulthood. It is not contagious and doesn't overly affect one's general health.
 

Causes

The exact cause of Atopic Dermatitis is unknown; however it is thought to be the result of an inborn defect of the skin, as it tends to run in families. People with this condition find the skin is very sensitive and usually dry and easily irritated by soap, detergents and woollen clothing. Atopic Dermatitis may be aggravated by hot weather and a wide variety of environmental factors both at home and at work. These include dust, cats, emotional stress and on more rare occasions, foods.
 

Treatment

No permanent cure is available, although with time atopic dermatitis usually improves. Most people are able to live comfortably with their skin condition with the following measures:

• Reduce contact with irritants.
• Reduce exposure to allergens.
• Emollients (moisturisers).
• Bath oils based on mineral oil or lanolin.
• Corticosteroids.
• Antibiotics.
• Antihistamines.
• Evening Primrose Oil / Star Flower Oil.
• Coal tar or ichthammol.

Hand dermatitis

Hand Dermatitis also known as ‘hand eczema’, often results from a combination of causes. Whatever the initial trigger, there are often a number of aggravating factors, which prevent it from clearing up.
 

Causes

Some people are more prone to hand dermatitis. There is often a personal or family history of asthma, eczema or hay fever (atopy). These people often have had, or have Dermatitis at other sites such as the elbows, behind the knees, the face or feet. Some patients have a personal or family history of psoriasis. Emotional stress can also make the condition worse.

Some chemicals, especially industrial solvents, detergents, acids, alkali and even water and friction, can strip the skin of its normal protective layers and oils. Prolonged exposure to such irritants, even in low concentrations, can trigger Hand Dermatitis and prevent it clearing up. Even occasional exposure can result in a flare of the condition.

Occasionally Hand Dermatitis is caused by true allergy to substances that the hands come into contact with. There are a number of possibilities including metals, perfumes, rubber, leather and preservatives. These may be tested for by special tests called patch tests. Contact with this material must be strictly avoided for the hand dermatitis to completely clear.
 

Treatment

• Avoiding wet work and contact with irritants.
• Emollients (moisturisers).
• Topical steroids.
• Oral or topical antibiotics.
• Oral steroids or ultra violet light therapy for severe cases.

Seborrhoeic dermatitis

Seborrhoeic dermatitis is a common, scaling rash that sometimes itches. Dandruff (pityriasis capitis) is Seborrhoeic Dermatitis of the scalp. Seborrhoeic Dermatitis may also occur on the eyebrows, eye lid edges, ears, the skin near the nose and skin-folds of the armpits and groin. Sometimes Seborrhoeic Dermatitis produces round, scaling patches on the middle of the chest or on the back.

Causes

Seborrhoeic Dermatitis is believed to be due to a proliferation of a normal skin inhabitant, a yeast called Pityrosporum Ovale (malassezia furfur). Patients with Seborrhoeic Dermatitis appear to have a reduced resistance to the yeast due to various factors including stress, fatigue, change of seasons and reduced general health.

It is not contagious or related to diet. Nervous stress and any physical illness tend to make Seborrhoeic Dermatitis worse but they do not cause it.
Seborrhoeic Dermatitis may appear at any age (usually after puberty), either gradually or suddenly. Seborrhoeic Dermatitis may last for years but usually disappears by itself. Often it gets better or worse without any apparent reason.
 

Treatment

There is no cure for Seborrhoeic Dermatitis. However, it can be kept under control. The treatment of Seborrhoeic Dermatitis depends on which part of the body is involved. Treatment will need to be repeated from time to time.

Scalp

• Medicated shampoos containing ketoconazole, selenium disulphide, zinc pyrithione, coal tar, and salicylic acid, used twice weekly for at least a month.
• Steroid scalp applications available on prescription, used intermittently.
• Tar creams applied several hours before shampooing.
   

Face, ears, chest and back

• Ketoconazole cream once daily for 2 to 4 weeks.
• Hydrocortisone cream up to twice daily for 1 or 2 weeks.

Perioral Dermatitis

Perioral Dermatitis is a common facial skin problem. It rarely occurs in men. Groups of itchy or tender small red spots appear most often around the mouth. They spare the skin bordering the lips (which then appears pale) but develop on the chin, upper lip and cheeks. The skin surface becomes dry and flaky. Often the skin around the nose is affected too, and sometimes that around the eyes. Patients who are susceptible to Perioral Dermatitis tend to have an oily face, at least in the
affected areas.
 

Perioral Dermatitis can be induced by:

• Not washing the face with soap and water.
• Applying face creams regularly to the area bounded by the cheek folds and chin, or around the eyes. These creams include moisturisers, cream cleansers, make-up foundation, and sunscreens.
• Applying topical steroid creams to the same area. The more potent the steroid cream, the more rapid and severe the Perioral Dermatitis which may result.
   

Treatment

• Discontinue applying all face creams including topical steroids, cosmetics and sunscreens.
• Do not apply face creams in the affected areas in the future, as the rash is very likely to reappear. Choose a liquid, gel or light milk sunscreen.
• Wash the face with warm water alone while the rash is present. When it has cleared up, wash with an ordinary toilet soap and water.
• Your doctor or dermatologist will usually also prescribe a course of oral antibiotics for six to twelve weeks. Antibiotic lotions tend to be less effective.
   

Perioral dermatitis sometimes recurs when the antibiotics are discontinued, or at a later date. The same treatment can be taken again.

If you think you may have Dermatitis, click the Book a Consultation button below to talk to a Dermatologist about your skin concerns.