Any substance with which the skin comes into constant contact may create allergic skin reactions in those persons who are hypersensitive to the specific substance for which recurrent and prolonged contact is necessary.
Harrison describes Dermatitis as : “It is an inflammation of the skin caused by and outside agent—a condition with many causes. The skin is red and itchy and small blisters may develop. In most cases the condition is associated with certain typical changes in the skin that are described as eczema (Eczematous Dermatitis).
Eczematous dermatitis may result from direct irritation of the skin by substance or it may be an allergic reaction to a particular substance that has been in contact with the skin, infected, or taken by mouth. In cases associated with a different reaction, the disorder is described as non-eczematous dermatitis. Industrial substances are a common cause of non-eczematous dermatitis, which is sometimes called occupational dermatitis. Other types of dermatitis can be caused by soaps or detergents (for example in diapers) or by sunlight. Treatment of dermatitis depends on the cases.”
Dermatitis can occur at any age but is more prevalent in old and aged persons due to their exposure to large number of substances to which they may become allergic. Certain irritating substances are known to cause dermatitis in majority of cases, but even non-irritating substances have been found to cause this condition. Generally a more concentrated substance is more likely to trigger or cause an allergic reaction which depends upon and varies from person to person.
As the list of allergy causing drugs and chemicals continues to inflate, the number of patients is also on the constant rise. It is not that reaction and intensity and severity of allergic reactions are uniform—it actually depends on sensitivity aspect of a person.
SYMPTOMS
□ Subsequent contact leads to appearance of the skin lesion within hours of the contact.
□ Itching in a particular spot which may engulf the surrounding area also.
□ Redness—which might progress to other areas.
□ Itches compels the patient to scratch and some patients scratch so vigorously that blood oozes out.
□ Raised lesions on the skin with fluid in them (say vesicles-, papules).
□ Confluence of lesions (in the chronic stage) which thicken the skin.
□ Bacterial infection and pus formation.
□ Lesions may or may not progress beyond the stage of redness, itching and vesiculation.
□ There may or may not be fever but the patient is restless.
Damage causing potential of the offending agent and the site of infection where dermatitis occurs, will help to determine the aetiological factor because, when specific parts of body are exposed or when they come into contact with a specific substance, it is not difficult to discern the causative factor. For instance, generally exposed parts of the body are more amenable to this disease, and that too only those which come into direct contact with an allergen. Feet, hands, neck, trunk, face, armpit and lower extremitites are impacted by dyes, fabrics, leathers. In some ladies even gold, gold plated silver ornaments may cause allergy of skin. Small children may get infected with dermatitis when some toys touch their more sensitive organs. If persons, infected with contact dermatitis, touch any part offender skin of the babies, they will most likely pass on the infection to the babies. Such persons are advised not to carry or touch the children until they are fully free from the infection.
PARTHENIUM ALLERGY (CARROT WEED ALLERGY)
When food grains were imported from U.S.A. about 43 years ago, parthenium weed, was (overtly or covertly) introduced to India as a contaminate with the imported wheat. This is an aggressive weed that abundantly grows various parts of our country without any aid from the soil.
RESULTANT SYMPTOMS
There is acute itching around face and sides of neck, gradually elbows, knees, ‘V of neck and ultimately engulf entire body. Itching results in swelling of the body and watery matter might ooze out therefrom. If itching is persistent and continues for a long time, the patient may develop scratches which might start to bleed also. Patch test can confirm or otherwise presence of allergy in patients.
ALLERGY CAUSED BY CERTAIN VEGETABLE PRODUCTS
Allergy due to some plant products is quite common and each plant product has its own specific traits. For instance the marking chalk (commonly used by washerman to mark identification marks on the clothes) produces vesicles which, in turn, produce further vesicles. If this fluid spells over to other parts, similar symptoms will appear thereon also, but actual users, rarely get allergic dermatitis. It is quite common with foreigner.
Calotropis Gingantea is another skin irritant. A milk like secretion cozes out of flowers. It can render a person blind, cause skin irritation, redness, puffing and pain also. Though the plant is used in certain ayurvedic preparations but should not be used by a common due to inherent dangers of causing severe dermatitis, including ulcers and eruptions also.