Skip to page content |

Tiscali Quicklinks. Please visit our Accessibility Page for a list of the Access Keys you can use to find your way around the site, skip directly to the main navigation, to the page content, or to more links within lifestyle.

Advertisement starts

Advertisement ends

Content Starts Here

Contact dermatitis

Health and Nutrition > Diseases > C

Contact dermatitis (Contd)

Written by Dr Virginia Hubbard, specialist registrar in dermatology and Dr Malcolm Rustin, consultant dermatologist

Chronic
Chronic irritant dermatitis often begins with a few patches of dry, slightly inflamed skin that become thickened with time.

Allergic contact dermatitis

Early The features of eczema develop at the site of contact. For example, the first sign may be an itch under an earring or along a waistband that contains rubber. The itch can develop into an area of redness with swelling and even small blisters that weep.

In contrast to irritant contact dermatitis, the reaction can extend beyond or occur in a different place from the site of contact. Occasionally, the appearance is that of urticaria (severely itchy raised red patches or wheals that can resemble insect bites, although these may be more irregular in shape). Rarely, swelling of the mouth and upper airways can occur, which is known as angioedema. This is serious and needs urgent medical attention.

Prolonged
If exposure to an allergen persists, the skin becomes drier, thicker and more scaly with a change in the pigmentation (colour).

How is contact dermatitis diagnosed?
The most important factor in making a diagnosis is the suspicion by you or your doctor that a substance in your environment is causing the dermatitis. Doctors should always think about the possibility of contact dermatitis when managing a patient with an eczematous (eczema-like) reaction. Two features are key to differentiating contact dermatitis from other causes of an eczematous rash and to determine the offending substances: the timing of onset or exacerbations and the part of the body that is affected.

Timing Allergic contact dermatitis usually occurs 48 to 72 hours after exposure, and will wax and wane depending on exposure.

Improvement of dermatitis during weekends or holidays is in favour of an occupational origin for the offending substance.

Occurrence or worsening at weekends suggests a hobby or environmental allergen.

Seasonal variation of dermatitis is seen in particular with plant allergens, which can also be aggravated by light.

Body site
Contact dermatitis usually starts in and often remains localised to the region most in contact with the offending substance. The pattern of affected skin is a vital clue in the origin of the substance (eg, a rash shaped exactly like your metal belt buckle could indicate an allergy to nickel).

Location of contact dermatitis and suspicious agents

Location Suspicious agent
Eyelids Eye makeup, airborne substances, nail polish
Earlobes or neck Metal jewellery
Forehead and hairline Hair dyes
Face Cosmetics (fragrance or preservatives), airborne substances
Armpits Deodorants
Hands Gloves, occupational hazards
Waistband Elastic or nickel in belt or trouser stud
Feet Shoes - leather, plastic, glues
All people who have an unusual dermatitis or one that resists treatment should have patch testing to test whether certain contact allergens are aggravating the dermatitis.

What else could it be?
Several types of eczema-like reaction can produce a similar appearance:

  • atopic eczema
  • seborrhoeic eczema (also know as seborrhoeic dermatitis)
  • discoid eczema
  • pompholyx (small water blisters on the hands and feet)
  • stasis or venous eczema
  • asteatotic eczema.

    • Confusingly, any of the above conditions can be exacerbated by an allergic or irritant component.

    Other skin conditions that should be considered are:

  • drug eruption - usually suggested by a history of a rash that occurs after starting a new drug treatment.
  • fungal infection - scrapings of the skin can be taken and examined under a microscope to make the diagnosis.

    • What can you do?

    Prevention

  • Use gloves and protective clothing when dealing with potentially irritant substances (even for repeated or prolonged exposure to water).
  • Thoroughly clean your skin if you come in contact with potential irritants.

    • Determine the cause

  • Make a list of substances that come in contact with your skin.
  • Record the timing of use of each substance and see if it relates to the timing of your dermatitis.
  • Record the body area exposed to each substance and see if it relates to the site of your dermatitis.

    • Treatment

  • Avoid the suspected irritant or allergen. This is sometimes not possible but use of protective clothing, such as gloves, can help. In some cases of occupational exposure, time away from work may be necessary.

    • What can your doctor do?
    Once the diagnosis is made, and suspicious substances have been identified, your doctor will advise you how to avoid the suspected/offending substance.

    Avoidance often resolves the dermatitis but if this is difficult or if the dermatitis is long standing, you will need drug treatments. Corticosteroids in the form of creams and ointments can be applied to the affected area to reduce the inflammation. Antihistamine treatments can sometimes help with redness and itching, particularly with urticaria.

    What can your dermatologist do?
    For some patients, a referral to a skin specialist (dermatologist) is needed. The dermatologist will:

  • discuss possible offending substances.
  • offer patch testing to check for allergies. Suspected allergens, including a battery of standard allergens, are applied usually to the back under aluminium discs or patches. These are left in place for 48 hours and then removed and the skin inspected. After a further 48 hours, the sites are inspected again. Reactions can range from mild redness to severe painful blistering. The results of the patch tests are then interpreted in the light of the history and possible previous exposure to the allergen.
  • discuss sources of the irritant or allergen and the relevance to you. Often an information sheet will be given.
  • suggest ways of avoiding contact with the substance.
  • suggest how to minimise exposure if avoidance is not possible, using:

    protective clothing

  • barrier creams (the use of barrier creams is controversial). Their efficacy varies depending on the constituents of the cream and the specific irritant. In general, barrier creams are a poor substitute for gloves. However, their use reminds both the employer and employee about the potential link between their job and dermatitis.

  • Discuss how a slight change in your work pattern may help. For example, a hairdresser with contact allergy to a constituent of permanent hair dye could avoid colouring and concentrate on cutting instead. A letter from your dermatologist to your employer may help. Sometimes a change in career needs to be considered.
  • Advise on suitable treatment in case of active dermatitis:

    suitable moisturisers

  • topical corticosteroids, which suppress the inflammatory reaction so should reduce redness, swelling and pain.

    • What is the outlook?
    Whether the dermatitis will settle or recur depends on several factors.

  • Can the cause be avoided? If it can, the dermatitis will usually settle within a week. If the irritant or allergen is widespread, eg nickel found in jewellery, studs, coins and keys, then minimising exposure will help prevent recurrence. In some severe cases, a change in career should be considered.
  • Does the patient also have atopic eczema? If so, then the risk is higher for developing a contact dermatitis.
  • Body site affected. Hand contact dermatitis is often the result of several irritants and allergens and is more difficult to manage.
  • Speed of recovery of the barrier function of the skin.
  • Superimposed infection can prolong dermatitis.
  • Treatments used can themselves act as irritants or allergens and delay recovery. This can occur with topical antibacterial creams, the constituents of medicated bandages or with herbal remedies.



    • <<Go To Page 1

    The documents contained in this web site are presented for information purposes only. The material is in no way intended to replace professional medical care or attention by a qualified practitioner. The materials in this web site cannot and should not be used as a basis for diagnosis or choice of treatment. Conditions for use

    Powered by netdoctor

    © Copyright 1998 - 2004 NetDoctor.co.uk - All rights reserved

    Related Links

    Health Search
    Search all
    Diseases
    Medicines
     
     
    Stop smoking now
    StayQuit is a medically proven smoking cessation programme that gives you the tools you need to quit smoking for good.
    Health Search
    Search all
    Diseases
    Medicines
     
     

    Advertisement starts

    Advertisement ends

    More Links Within This Section

    -->
    health advice

    Page Footer

    print now Print now send to a friend Send to a friend related articles Related articles related products Related products

    Check shares

    Check shares
    Look up latest prices
    more...

    Best Loans

    Best Loans
    Search for the best rate.
    more...

    Dating

    Dating
    Find the love of your life
    more...

    TV guide

    TV Guide
    What's on the box?
    more...
    | Advertise | Press | Work at Tiscali | Site Map | Service Status | Help | Contact Us
    © Tiscali 2008
    IT | NET

    Access keys


    You will need to use different key combinations in order to use access keys depending on your internet browser, find out which on our accessibility page.
    • (0) Navigate to Accessibility page.
    • (1) Navigate to Home page.
    • (2) Navigate to My email.
    • (3) Navigate to My Account.
    • (4) Navigate to Site Map page.
    • (5) Navigate to Contact us page.
    • (6) Navigate to Members channel.
    • (7) Navigate to Services channel.
    • (8) Navigate to News & Info channel.
    • (9) Navigate to Entertainment channel.
    • ([) Skip down to the Primary navigation block.
    • (]) Skip down to the more links within this section block.
    • (=) Bypass all navigation and jump to the content.