Irritant Contact Dermatiis

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•  The pathogenesis of contact dermatitis involves resident epidermal cells, dermal fibroblasts, endothelial cells, and various leukocytes interfacing with each other under the control of a network of cytokines and lipid mediators. Keratinocytes play an important role in the initiation and perpetuation of skin inflammatory reactions through the release of and responses to cytokines. resting keratinocytes produce some cytokines constitutively. a variety of environmental stimuli (eg, ultraviolet light, chemical agents,) can induce epidermal keratinocytes to release the following cytokines. Inflammatoru cytokines ( interleukin 1, tumor necrosis factor-alpha)  Chemotactic cytokines ( interleukin 6, interleukin 7, interleukin 15, granulocyte-macrophage colony-stimulating factor, transforming growth factor-aloha) Cytokines regulating humoral versus cellular immunity (interleukin 10, interleukin 12, interleukin 18) Intercellular adhesion molecule 1 promotes the filtration of leukocytes into the epidermis in cutaneous inflammatory reactions, including irritant contact dermatitis. Intercellular with a history of atopic dermatitis are prone to develop irritant contact dermatitis of the hands. Polymorphisms in the flaggrin production, may alter the skin barrier and are a predisposing factor for atopic dermatitis. FLG null aleles are associated with increased suspeptibility to chronic irritant contact dermatitis ( Hogan, (2013).  

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• Common in the United states in occupations that require repeated hand washings or repeated exposure of the skin to water, food materials, and other irritants. High-risk occupations include cleaning, hospital care, food preparation, and hairdressing.The prevalence of occupational hand dermatitis was found to be 55.6% in 2 intensive care units and was 67% in the most highly exposed workers. Hand-washing frequency of more than 35 times per shift was associated strongly with occupational hand dermatitis. International Statistics  In Denmark, cleaners comprise the greatest number of affected workers, but culinary workers have the highest incidence. A higher proportion of prolonged sick leave is seen among those in food-related occupations compared with those in wet occupations.  The incidence rates of contact dermatitis in Germany were 4.5 per 10,000 workers for irritant contact dermatitis, compare with 4.1 per 10,000 workers for irritant contact dermatitis, compared with 4.1 per 10,000 workers for allergic contact. The highest  irritant contact dermatitis annual incidence rates were found in hairdressers (  46.9 cases per 10,000 workers per year), (bakers, 23.5 cases per 10,000 workers per year), and pastry cooks (16.9 cases per 10,000 workers per year). Sexual difference in incidence  Irritant contact dermatitis is significantly more common in women than men. the highest frequency of hand eczema  in women in comparison with men is caused by environmental factors, not genetic factors.Occupational irritant contact dermatitis affects women almost twice as often as men, in contrast to other occupational diseases that predominately affect men. Women are exposed more highly to cutaneous irritants from their disproportionately greater role in housecleaning and the care of small children at home. In addition, women predominately  perform many occupations at high risk forirritant contact dermatitis (eg. hairdresser, nursing). Age-related differences in incidence Irritant contact dermatitis may occur at any age. Many causes of diaper rash dermatitis are irritant contact dermatitis resulting from direct skin irritants present in urine and especially feces. Older persons have drier and thinner skin that does not tolerate soaps and solvents as well as younger individuals. Occupational hand eczema often is associated with persistent dermatitis and prolonged sick leave, with substantially greater severity among those with occupational irritant cotact dermatitis and atopic dermatitis and age older than 50 years ( Hogan, ( 2013).  

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• Solvents- such as alcohol or xylene remove lipids from the skin, producing direct irritant contact dermatitis and rendering the skin more susceptible to other cutaneous irritants, such as soap and water. Metalworking fluids, Neat oils most commonly produce folliculitis and acne. They may cause irritant contact dermatitis ( as well as allergic dermatitis). Water-based metalworking fluids often cause irritant contact dermatitis in exposed workers; surfactants in these fluids are the main culprit.cumulative irritant contact dermatitis- is a common in many occupations that often are termed "wet work". Healthcare workers wash their hands 20-40 times a day, producing cumulative irritant contact dermatitis. Similar exposures occur among individuals who wash hair repeatedly or in cleaners or kitchen workers.Multiple skin irritants may be additive or synergistic in their effects. Alcohol-based hand-cleaning gels cause less skin irritation than hand-washing and therefore are preferred for hand hygiene from the dermatological point of view. An alcohol-based hand-cleaning gel may even decrease, rather than increase, skin irritation after a hand-wash, owing to a mechanical partial elimination of the detergent.Microtrauma- Fiberglass produces direct damage to the skin, usually manifested by pruritus that may result in excoriation and secondary skin damage. Cutaneous irritation primarily is caused by fiberglass with diameter exceeding 4.5 um.Controversy surronds whether individuals with dermatographism are more susceptible to fiberglass dermatitis. Most workers with irritant contact dermatitis resulting from fiberglass develop hardening, in which they tolerate further cutaneous exposure to fiberglass. Many plant leaves and stems bear small spicules and barbs that produce direct skin trauma.Mechanical traumaPressure produces callus formation. Pounding produces petechial or ecchymosis. sudden trauma or friction produces blistering in the epidermis. repeated or rubbing or scratching produces lichentification. sweating and friction appear to be the main cause of dermatitis that appears under soccer shin guards in children.Rubber gloves- may provoke direct cutaneous irritation. Many workers complain of irritation from the powder in rubber gloves. Remember that gloves compromised by a hole may allow an irritant to enter, occlusion dramatically increases skin damage from the irritant. Occulsion accentuates the effects, good or bad, of topical agents. Kerosene may produce skin changes similar to that of toxic epidermal necrolysis following occluded cutaneous esposure. Excessive amounts of ethylene oxide in surgical sheets also may produce similar changes.Sodium lauryl sulfate- a chemical found in some topical medications, particularly acne medications, as well as a range of soaps and shampoos. It is also a classic experimental cutaneous irritant.Hydroflouric acid- acid burn is a medical emergency. Remember that onset of clinical manifestations may be delayed after the acute exposure ( this is crucial to diagnosis). Unfortunately, hydrofluoric acid burns are most frequent on the digits, where the pain is most severe and management is most difficult.Alkalies- skin surfaces normally have an acidic ph, and alkalies (eg. many soaps) produce more irritation than many acids. the "acid mantle" of the stratum corneum seems to be important for both permeability barrier formation and cutaneous antimicrobial defense. Use of skin cleansing agents, especially synthetic detergents with aph of approximately 5.5 rather than alkaline ph, may help prevent skin disease ( Hogan, ( 2013). 

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• patients report both itching and pain caused by fissuring hyperkeratonic skin ( chapping ). Pain, burning, stinging, or discomfort exceeding pruritis occur early in the clinical course. a major occupational disease; skin disorders compromise 40% of occupational illnesss. A occupational history from adults suspected of irritant contact dermatitis. Most affected workers have degree of permanent injury that is lower than other occupational disease. occupationa lcontact irritant dermatitis typically  to irritant contact dermatitis,   effects workers who are new to a job, who are  constitutionally more susceptible to irritant contact dermatitis, or who have not learned to protect their skin from cutaneous irritants, individuals with a history of a topic dermatitis ( especially of the hands) are more susceptible to irritant contact dermatitis  particularly of the hands. Onset of symptoms occur within minutes to hours of exposure in simole acute irritant contact dermatitis Acute delayed irritant contact dermatitis is characteristics of certain irritants, such as benzalkonium chloride  (eg. zephiran, a preservative and disinfectant), which elicits a deferred ( 8-24 h after exposure) inflammatory reaction. Cumulative irritant contact dermatitis typically occurs with exposure to weak irritants rather than strong ones. Often, the exposure (eg. water) is not only at work but at home.

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• No diagnostic test for irritant contact dermatitis. te diagnosis rest on the exclusion of other cutaneous diseases, (especially allergic contact dermatitis ) and on the clinical appearance dermatitis at a site sufficiently exposed to a known cutaneous irritant. Lab oratory studies are generally of little value in proving a diagnosis of contact dermatitis., however they may be of value in eliminating some disorders from the differential diagnosises. Findings of significantly elevated serum immunoglobulin e occasionally are useful to substantive an atopic diathesis in the abscence of a personal or family history of atopy ( Hogan, ( 2013)..

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• adaptive immunity is a very LR-agonists and cytokines. Activation of B cells also result in differation into plasma and increased cytokine production. PPARS ( Hogan, (2013).

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• Jack is a 27-year-old male who presents with redness and irritation of his hands. He reports that he has never had a problem like this before, but about 2 weeks ago he noticed that both his hands seemed to be really red and flaky. He denies any discomfort, stating that sometimes they feel “a little bit hot,” but otherwise they feel fine. He does not understand why they are so red. His wife told him that he might have an allergy and he should get some steroid cream. Jack has no known allergies and no significant medical history except for recurrent ear infections as a child. He denies any traumatic injury or known exposure to irritants. He is a maintenance engineer in a newspaper building and admits that he often works with abrasive solvents and chemicals. Normally he wears protective gloves, but lately they seem to be in short supply so sometimes he does not use them. He has exposed his hands to some of these cleaning fluids, but says that it never hurt and he always washed his hands when he was finished.