What is Contact Dermatitis?
Contact dermatitis is among the top reasons for most visits of patients in primary clinics. It is defined as a skin reaction characterized by skin inflammation after contact in skin of foreign substances or from triggers coming from the environment and other forms of exposures. This condition of the skin is neither non-life threatening nor contagious although the skin reaction is rather very discomforting. There are however, skin reactions from sources that would need immediate or urgent action in relieving the skin reaction as the reaction may cause anaphylactic shock and thereby calls for an emergency intervention.
Contact dermatitis is generally divided in two main forms although there are other types of the dermatitis. The two main types of dermatitis are classified according to the source of skin reaction.
Allergic contact dermatitis
This is a skin reaction arising from exposure to irritants. The hypersensitivity reaction in this type is delayed in triggering the immune system of a patient who has been previously exposed or sensitized to allergen. The reaction is often from small or simple structure of non-protein molecule and an individual can only become allergic if the immune response has been triggered by at least one incidence or previous exposure to sensitized contactant. This dermatitis resulted from an immune response mediated by a certain blood cell in identifying specific allergen. The reaction however, is delayed following an exposure with exposure usually requiring 24 to 48 hours prior to manifestation.
Irritant contact dermatitis
This is the most common form of contact dermatitis ad which is a type of skin reaction occurring as a response to direct injury to the skin not associated with allergy. The onset of dermatitis is immediate following an exposure and does not require previous exposure from trigger while severity of reaction depends on the period of stay of contactant in the skin. The longer the trigger remains on the skin, the more severe the reaction will get.
Other form of contact dermatitis includes photocontact dermatitis which is the result of all forms of dermatitis and activated by the ultraviolet light upon exposure to sunlight. The area affected in this form of dermatitis is only the part not covered and exposed to sunlight.
Contact dermatitis in any form can affect the people from all ages although the prevalence and type of dermatitis has been linked to the age group such as adults mostly experience the irritant contact dermatitis usually from the use of soaps, lotions and creams while infants predominantly experience the same type of dermatitis with adults and is usually in the buttocks and due to diaper wear.
Contact dermatitis in any form mostly occurs in the hand as the common area for its manifestation. This dermatitis is marked by inflammation of the skin and red itchy rash. The difference however, of development in both the irritant and allergic reaction is that in irritant the rash immediately appear after contact in the skin while in allergic contact dermatitis the rash appears within 24 to 48 hours after exposure to allergen. Although both or all forms of dermatitis are marked by spongiosis of epidermis, each form has their distinct cardinal feature to differentiate them from one to another.
Signs and Symptoms of Allergic Contact Dermatitis
- Red and itchy rash usually develop within a day or two following exposure from allergen while the rash is usually confined in one area only where the activator has touched the skin
- Very pruritic with papules and vesicles based on an erythema and with borders that are distinct
- Severe itchiness and burning sensation can be felt over the affected area of the skin
- Dermatitis in allergic form can spread over a period of time
Signs and Symptoms of Irritant Contact Dermatitis
- Hands are the usual area affected in this form of dermatitis
- Rash immediately appears after initial contact with the trigger
- Pruritus is mild with burning sensation and often painful rather than itchy
- Borders are indistinct and more on macular erythema and fissures rather than vesiculation
- Skin reaction has little chance of spreading
There are some skin reactions in contact dermatitis which is not confined in the area that has come into contact with the trigger but rather appear in some part that may or may not be distal to the point of origin or the skin reaction may extend from its original site of contact.
Contact dermatitis has number of factors considered for the skin reaction to generally start while both forms of dermatitis differ from the nature of origin.
Allergic contact dermatitis arose from a response of the immune system to a simple structure of non-protein molecule. The onset of this form of dermatitis is following the previous exposure to specific trigger that has sensitized an individual. Strong allergen only takes one exposure while it may take multiple exposures to weaker allergen before one can develop allergic contact dermatitis. Common allergens include the following:
- Cream and lotions
- Soaps and other strong detergent
- Rubber and other latex
- Cosmetic products and other scents
- Nuts specially cashew nuts and others with similar substance of urushiol that can be found in poison ivy
- Medicines such as antibiotics and antiseptic
Irritant contact dermatitis is the result of direct injury to the skin from triggers that requires only a single exposure. Such triggers may include the following:
- Plants belonging to spurge family
- Alkalis in soap and other detergents
- Topical medications and shampoos containing sodium lauryl
- Contact with hydrofluoric acid and other chemical substances
Primary treatment for both forms of contact dermatitis is in the elimination of triggers. It is advisable to immediately wash the affected area with cool clean water and soap to remove the trigger. Mild cases of both allergic and irritant contact dermatitis can be treated with over-the-counter creams that contain hydrocortisone to relieve the symptoms of itchiness and redness. Stronger strength of creams can be prescribed by doctors for severe cases of contact dermatitis whether allergic or irritant. Inflammation of skin can be reduced and relieved with oral medication of corticosteroids.