Occupational hyperpigmentation

Phytophotodermatisis is a phototoxic reaction caused by the interaction of ultraviolet radiation and a photoactive substance, such as any of the ftirocou-marins, deposited on the skin surface after contact with various species of plants (Table 1) (Pathak et al. 1962 Pathek 1986). The dermatitis is usually vesicular or bullous healing with characteristic residual hyperpigmentation. Phytophotodermatitis is a well-known cause of occupational hyperpigmentation and has been... 

Acute inhalation exposures have resulted in irritation of the upper respiratory tract, even leading to nasal perforations. Occupational exposure to arsenic compounds results in hyperpigmentation of the skin and hyperkeratoses of palmar and plantar surfaces, as well as dermatitis of both primary irritation and sensitization types. Impairment of peripheral circulation and Raynaud phenomenon have been reported with long-term exposure. ... 

Most, if not all, occupational illnesses associated with 2,4,5-T (such as chloracne) have been found to be the result of product contamination with TCDD. TCDD is extremely toxic to animals, and exposure has also been associated with liver function impairment, peripheral neuropathy, personality changes, porphyria cutanea, hypertrichosis, and hyperpigmentation in humans. TCDD is a chlorinated dioxin, one of a large number of related compounds referred to as dioxins it has no functional use and is not intentionally produced. It has been identified as the responsible toxic agent in several industrial disasters, such as accidental releases at Nitro, WV in 1949, and at Seveso, Italy in 1976. " The role of dioxin contaminants must also be considered in the discussion of 2,4,5-T toxicology. 

Bentley-Philips B, Bayles MAH (1971) Occupational koilonychia in toe nails. Br J Dermatol 85 140-144 Bergfeld WF, McMahon JT (1987) Cutaneous metalloid hyperpigmentation. In Callen JP, Dahl MV, Golitz LE, Stegman SJ (eds) Advances in dermatology, vol 1. Yearbook, Chicago, pp 123-124... 

Cutaneous photosensitivity (Emmett 1987 Rietschel and Fowler 1995) is due to the presence of an exogenous chemical that absorbs ultraviolet radiation and initiates photochemical events in normal tissue. A number of substances used industrially or contacted occupationally can cause occupational photosensitivity, but usually only phototoxic reactions cause significant hyperpigmentation. 

In conclusion, when an epidemic of hyperpigmentation occurs in the occupational setting, a diagnosis of pigmented contact dermatitis should be considered. However, in isolated, non-occupational cases, pigmented contact dermatitis is more likely to be missed. 

Fisher A (1982) Leukoderma from bleaching creams containing 2% hydroquinone. Contact Dermatitis 8 272-273 Fisher A (1986) Acne venenata in black skin. Cutis 37 24-26 Fisher A (1994) Differential diagnosis of idiopathic vitiligo. Part III occupational leukoderma. Cutis 53 278-280 Fisher A (1995) Contact leukoderma (vitiligo) hyperpigmentation and discolorations from contactants. In Rietschel R, Fowler JJ (eds) Fisher s contact dermatitis, 4th edn. Williams Wilkins, Baltimore, pp 765-777... 

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