Irritant contact eczema
Irritant contact eczema (dermatitis) is the second most common cause of occupational health problems, after muscle and joint pains and injuries.
The most common cases of irritant contact eczema are commonly found in the same types of occupations. Jobs that require an employee to repeatedly expose their skin (often their hands) to the same chemicals are the most likely place to find cases of this form of eczema. Hairdressers, cleaners, catering workers, food processors, and fish handlers are all jobs that require employees to repeatedly expose their hands to water. Prolonged exposure to water can swell the surface cells of the skin and disrupted the normally tight joints between them, which will expose the deeper more sensitive layers of tissue below. In metal engineering or engine mechanics, light oils are commonly in constant contact with skin. As many as half of the workers in this industry have irritant contact eczema, It is just accepted as “part of the job”.
Having one type of eczema puts you at higher risk of having another. People with eczema generally have sensitive skin. So if you have a background atopic eczema you may be more likely to develop irritant contact eczema.
Its not just a problem found in the work environment several everyday household chores can lead you to exposure to all kinds of irritating chemicals. Some household irritants may be obvious irritants such as bleach or other types of cleaners. Some more discrete irritants may be scented soap or shampoo residue, or even brands of detergent that have scent, lubricants or brighteners. Hobbyists should take extra care when working with paints oils and different types of glues.
Diagnosis
Irritant contact eczema looks the same as other types of eczema. The connection with the work environment may be obvious if there is a constant exposure to an irritant or if the job is of the “wet work” type. Otherwise it may take a long time and close observation to establish the source of irritation.
Therefore a diagnosis of irritant type contact eczema requires good records of exposure and knowledge of possible irritants. Also negative patch tests are the best way to exclude allergic contact dermatitis.
Treatment
Removing the source of irritation would be ideal, but unfortunately is not always practical. Should this be case, then the goals for treatment can be to reduce symptoms. Unfortunately even mild exposure can cause reaction.
When contact with an irritant is unavoidable, protective gloves are essential. Since rubber and latex can also cause eczema in some people, gloves should have cotton inserts or liners to prevent direct contact with the glove itself.
Frequent moisturizing is necessary especially with “wet work” type jobs. Barrier creams can be beneficial, but can become counter-productive if less care is taken while using them (cream alone can not protect you). A beeswax cream can protect hands and hold in moisture. Unnatural scented beeswax creams or ones with extravagant ingredients can irritate skin. Simple ingredients tend to be the best (fewer ingredients less possible irritants).

Allergic Contact Eczema
Allergic contact eczema is generally defined as tissues swelling or becoming irritated after contact with an allergen. The cells of the immune system work in various ways for skin disease.
The skins first reaction to an allergen (a rash), is referred to as immediate hypersensitivity. This is due release of histamine chemicals by the immunity cells within the layers of the skin.
The second part of the reaction is referred to as delayed hypersensitivity. The population of cells the react against the invading substance must build up from a small number of memory cells that recognize the allergen.
After two or three days these cells will begin to give rise to other that will switch on other defense mechanisms, such as releasing of chemicals that attract scavenger cells of the immune system. The severity of the reaction may vary depending on one’s level of sensitivity, and the amount of exposure to the allergen.
Common allergens
The reasons that make some substances prone to being allergens in unknown, but some of the common culprits are.
• Nickel - a white metal commonly found in costume jewelry, jean studs, metal watch straps, bra fasteners, and several other metals can possibly cause a reaction.
• Perfumes – Balsam of Peru is a common ingredient of many perfumes and is known for causing a contact allergy.
• Rubber and latex – these and other related chemicals can be found in clothes shoes and protective wear.
• Potassium dichromate – can be found in cement, leather, and matches.
• Hairdressing chemicals – (Paraphenylenylenediamine).
• Scented soaps – soaps that leave any scent are more likely to cause irritation.
• Medications – Lanolin, neomycin (antibiotic), fusidic acid ( antibiotic), steroid creams and cetearyl alcohol (used in emollient creams).
• Colophony – resin from spruce trees, used in sticking plaster adhesive.
• Detergents – residue left in clothing by detergents can irritate skin.
• Plants – both by direct contact and by contact with airborne particles.

Some foods have been prone to causing skin reactions
• Sugar
• Flour /dough
• Citrus fruits and their peel
• Other fruits and vegetables
• Spices, herbs, and seasonings ( horseradish, mustard, and garlic)
• Fish and sea foods
• Meat and poultry
This is by no means a list of all possible allergens that can cause contact eczema.
Some of the products that are intended for treatment of eczema and similar conditions are in fact themselves possible sources of irritation. So if the treatment methods seem to be making the symptoms worse or proving resistant to treatment, Suspicion of the treatment method itself or another daily routine that your body may have become sensitized to may be responsible.
Any one with eczema or sensitive skin should use only products they know will not irritate their skin when searching for the source of the allergen. This would include products such as soaps or laundry detergent that leave residues. Perfumes or different foreign scents can often be the responsible allergens in most products. Obviously if you wash your clothes or your hands with something and it smells like that product it has been saturated by its residue. The residue left contacting your skin can often contain ingredients that certain people will be allergic to.

Features of Contact allergic Eczema
The rash will be the first sign to appear that the skin has contacted an allergen. Later the rash can and will often spread far away from the original contact site. This is because the immune cells become activated and begin to migrate to other regions of the body through the bloodstream.
If allergic contact eczema is suspected, It is important to keep a close medical records of the rashes locations and developments.
In some cases the causes of the eczema may obvious, such as scaly reaction beneath the watch or a ring around a piercing location. If a long period of time has passed since the first exposure without records it may be difficult or impossible to distinguish between allergic contact eczema and other types of eczema.
There may be difficulty distinguishing between allergic contact eczema (an immune response) and irritant contact eczema (a direct reaction against an irritating substance).
In practice and treatment this is not so important because the treatments of the conditions are so similar. If possible should be determined for future care and prevention.
“Patch testing” is a common method, which should only be done by qualified medical practitioners. Patch testing consists of subjecting a person’s skin against a series of common contact allergens to try and determine what substances that person should be avoiding.
If allergy testing shows that the allergen can be removed, the problem is likely to stop. Sensitivity will remain dormant until later exposure. This not always the case particularly individuals with hand eczema, this remains unclear.
Moisturizers and steroid creams do work for contact eczema, but how much the conditions improve is based on level of sensitization and frequency of exposure to the allergen.
If the offending substance is continually being reapplied to the skin, one will end up using a lot a treatment for little effect.
(Information Source: www.netdoctor.co.uk)