Exogenous dermatitis

PIH can be observed after endogenous or exogenous inflammatory conditions. Essentially any disease with cutaneous inflammation can potentially result in PIH in individuals capable of producing melanin. Several skin disorders such as acne, atopic dermatitis, allergic contact dermatitis, incontinenti pigmenti, lichen planus, lupus erythematosus, and morphea have PIH as a predominant feature. Exogenous stimuli,both... 

The incidence of adverse effects with hydroquinone increases in proportion to its concentration. A relatively common side effect is local irritation, which may actually exacerbate the discoloration of the skin being treated. Allergic contact dermatitis occurs less commonly. A rare but more serious complication is exogenous ochronosis, in which a yellow-brown pigment deposited in the dermis results in blue-black pigmentation of the skin that may be permanent. 

Camarasa JG, Serra-Baldrich E. Exogenous ochronosis with allergic contact dermatitis from hydroquinone. Contact Dermatitis 1994 31(l) 57-8. 

Rashes which evolve from contact dermatitis or which arise when patients already sensitized by exogenous contact ingest the allergen or receive it parenterally (hematogenous contact eczema) display special features. There is a dense eruption of papulovesicular lesions side by side with superficial eczematous changes. 

A complex interplay of exogenous risk factors and the endogenous disposition is believed to be responsible for the occurrence and course of irritant contact dermatitis (ICD) in humans. To prevent its appearance, determinants of disease development, also known as risk factors, must be identified. 

The induction of experimental dermatitis by means of model irritants represents a method for reproducing ICD in a standardized way and can be employed both for evaluating skin reactivity in high-risk subjects and for monitoring the response and adaptation to the occupational milieu. Skin reactivity to exogenous substances may vary with respect to both the intensity and course of barrier damage and the inflammatory response. Transepidermal water loss (TEWL) and capacitance measurements and instrumental evaluation of skin blood flow, erythema and edema represent the methods for the quantification of different aspects of experimentally induced irritation. 

Thune P (1996b) The effects of detergents on hydration and skin surface lipids. Clin Dermatol 14 29-33 Wahlberg JE, Stenberg B (1991) Skin problems in the office environment. In Menne T, Maibach HI (eds) Exogenous dermatoses environmental dermatitis. CRC Press, Boca Raton, pp 327-338... 

Man MQ, Feingold KR, Elias PM (1993) Exogenous lipids influence permeability barrier recovery in acetone-treated murine skin. Arch Dermatol 129 728-738 Marks JG Jr, Fowler JF Jr, Sheretz EF, Rietschel RL (1995) Prevention of poison ivy and poison oak allergic contact dermatitis by quaternium-18 bentonite. J Am Acad Dermatol 33 212-216... 

Combined influences of endogenous and exogenous factors may lead to the development or to aggravation of hand eczema (Nilsson 1985). Atopic eczema in childhood has been found to be a more important predictive factor for hand eczema than occupational exposure (Meding and Swanbeck 1990). In a population of individuals with atopic dermatitis in childhood, 57% developed sporadic or continuous hand eczema during concrete work (Rystedt 1985). When compared with other occupations, such as the metal industry, cleaning, and even office work, equal prevalences were found. 

Metal workers are exposed to numerous exogenous factors that play a substantial role in tbe development of allergic as well as irritant contact dermatitis (ICD). Even though nickel is regarded as the most frequent source of all reported metal allergies [i], metal-work fluids (MWFs) are the most important cause of irritant hand dermatitis. Other factors such as metal dust, friction, pressure, heat and humidity also contribute to the irritation of the skin [2]. However, the metal industry is a wide fleld, and exposure may vary widely depending on the kind of job and the type of metal industry. 

Exposure to risk factors for the development of contact dermatitis may vary widely depending on the kind of job and, even more, on the type of metal industry. A multiplicity of exogenous factors and variability in individual behavior make the estimation of dermal exposure at work very difficult [7]. In all cases, the industrial physician must look at the room ventilation, stress the importance of protective gloves and creams. However, frequent washing of the hands to remove the irritant/allergen also seems to be important [8]. 

Jirasek L (1979) Occupational exogenous siderosis of the skin. Contact Dermatitis 5 334-335... 

Seneschal ], Kubica E, Boursault L, Stokkermans ], Labreze C, Milpied B, et al. Exogenous inflammatory acne due to combined application of cosmetic and facial rubbing. Dermat 2012 244(3) 221-3. 

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