This develops as an itchy skin condition caused by the contact of allergic materials. The outer layer of the skin acts as a protective barrier against harmful substances and when certain materials remove the oils or fats from the skin layer, it can penetrate the skin causing reactions. Usually, the individual may not present allergy with initial contact with allergen materials and can continue without any reaction for several years.
Causes
The allergy starts with a process known as sensitization which is the penetration of allergen materials into the skin and may present no signs or symptoms. When the material successfully penetrates the outer layer of the skin, it combines with the skin proteins which are passed throughout the body. The white blood cells known as lymphocytes recognize the ‘foreign’ material when the individual is re-exposed to it. Hence, the body’s immune system reacts with the allergen by releasing various protective chemicals that can damage the tissue. This results in the itchiness, redness, swelling and the formation of blisters. Some of the contributing factors of developing allergic contact include an already existing skin condition such as irritant contact dermatitis, hereditary factors, environmental factors and friction against the skin. Other occupational risks include exposure to various materials such as rubber, turpentine, nickel, resins, formaldehyde and pesticides.
Symptoms
When the skin becomes sensitive to the allergen material, further exposure to it will result in a rash. This may not develop for a day or two but could begin within a few hours or after a week. The body’s reaction to the allergen materials can cause itching, redness, swelling or can create small blisters on the skin. This usually affects the site of contact but the severe cases can spread over large areas of the body. Some examples of typical allergic contact dermatitis include eczema of the wrist as the result of contact with nickel from watch strap, hand dermatitis caused by chemicals used for the manufacture of gloves and the itchy red face from contact with a chemical known as methylisothiazolinone used in hair-wash products.
Diagnosis
The diagnosis of allergic contact dermatitis is by examination of the skin and in identifying the allergen material. This can also include evaluating the individual’s working environment and the type of materials they are in contact every day. When the type of allergen is easily identified, no further tests may be required. In most cases, the rash disappears on its own in the absence of contact with the allergen but can occur again even with slight exposure. The diagnostic test of this condition is usually done with a patch test where a small amount of the allergen substance is exposed to the skin to evaluate if inflammation at the site occurs which is a positive indication.
Treatment
The only effective remedy is the avoidance of contact with the allergen substance. Protective glove or clothing should be used particularly when in contact with the material, however, certain chemicals can penetrate the gloves, hence expert advice should be obtained. The treatment can include anti-inflammatory creams, ointments and skin cleanser.
References
https://www.ccohs.ca/oshanswers/diseases/allergic_derm.html
http://www.dermnetnz.org/topics/allergic-contact-dermatitis/
http://www.aocd.org/?page=AllergicContactDerma
