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Biomedical subjects

C G Mathias

Publications and source records attributed to C G Mathias.

At least 37 records · Page 2Linked to original sources

Dermatitis from plastic tote boxes impregnated with an antistatic agent.

An outbreak of dermatitis occurred among employees of a microelectronics firm. In a cross-sectional epidemiologic investigation, we found that dermatitis of the hands or arms had occurred among 14 of 29 (48.3%) employees of the incoming inspection department where plastic tote boxes recently purchased from one manufacturer had been used, compared to only one case among 17 (5.9%) employees in another department which had not used these boxes. Affected workers could detect an oily film on the surfaces of these new boxes, but not on older ones. We identified the oily film to be a surface accumulation of bis-hydroxyethyl-tallow amine (BHETA), an antistatic agent with which the tote boxes had been impregnated. Subsequent toxicologic investigation established that BHETA could provoke both follicular and nonfollicular irritant dermatitis, and was also a potential skin sensitizer. Antistatic agents should be considered as potential causes of dermatitis among employees who handle electrical parts transported in plastic boxes, particularly when affected employees can detect an oily film on the box surfaces.

Amines↗

Occupational vitiligo due to unsuspected presence of phenolic antioxidant byproducts in commercial bulk rubber.

We investigated the occurrence of cutaneous depigmentation (vitiligo) among employees of a company that manufactured hydraulic pumps. The interiors of these pumps were injection-molded with rubber. We identified a small but significant cluster of vitiligo cases among a group of employees who frequently handled the rubber used in this injection molding process. Although none of the additives specified in the rubber formulations was a phenolic or catecholic derivative, known to be potential causes of chemically induced vitiligo, gas chromatographic analysis identified a para-substituted phenol (2,4-di-tert-butylphenol, DTBP) in solid samples of the most frequently used rubber. Surface wipe analysis confirmed that workers could be exposed to DTBP from simple handling of the rubber. We subsequently established that the solid bulk rubber used as the base in these stock rubber formulations contained both DTBP and smaller quantities of p-tert-butylphenol. Both had formed as unsuspected byproducts during chemical synthesis of two antioxidants added to the solid bulk rubber by a major rubber supplier. We conclude that the unsuspected presence of potential chemical depigmenting agents in solid bulk rubber, from which industrial rubber products are formulated, may contribute to the occurrence of occupational vitiligo, and that a simple review of ingredients in rubber formulations is inadequate to detect their presence.

Adult↗

Post-traumatic eczema.

Thirteen cases of eczema that followed acute cutaneous trauma were observed. On the basis of the present case series, the following conclusions may be drawn: 1. Cutaneous trauma may precipitate eczema. 2. The trauma is sufficient to cause obvious tissue damage accompanied by an inflammatory or regenerative response. 3. Eczema usually begins within a few weeks of acute injury at the site of the cutaneous trauma. 4. Eczema may occur as an isolated idiopathic reaction or as an isomorphic reaction either preceding or following the appearance of an endogenous eczematous condition in nontraumatized skin. 5. Individual lesions of post-traumatic eczema may persist or recur for long periods of time. 6. The occurrence of post-traumatic eczema following occupational injury has important medicolegal implications.

Adult↗

Granulomatous reaction to purple tattoo pigment.

An acute dermatitis overlying an immunologic granuloma was noted at the site of purple "dye" injection in a man with multiple multicolored tattoos. The skin reaction was observed 3 weeks after the injection, which proved to contain manganese, the usual metallic salt used for purple colored tattoos. Atomic absorption spectrometry showed a large amount of manganese in the biopsy specimen. Neither the dermatitis nor an immunologic granuloma could be reproduced with manganese salts or the alleged tattoo pigment. In addition, his peripheral blood lymphocytes were shown to be normal both in subset distribution and in their function, but these cells did not respond by blastogenesis to dilutions of the alleged pigment or to 2 manganese salts tested.

Adult↗

Knuckle pads in live-chicken hangers.

A study of live-chicken hangers in a poultry processing plant demonstrated a high prevalence of callosities over the knuckles (knuckle pads) of both hands. Knuckle pads were observed in 56% (23/41) of live-chicken hangers, but in no (0/41) workers from other departments (p less than 0.001). The probable cause was the repeated striking and sliding of the knuckles against metal shackles in which live birds were being placed. Additional medical and ergonomic evaluation would be worthwhile to confirm the probable cause, to determine whether associated tissue disorders are present in the digits of chicken hangers who develop knuckle pads, and to suggest preventive measures.

Adult↗

Surveillance of work-related cold injuries using workers' compensation claims.

The usefulness of workers' compensation claims for the surveillance of occupational injuries was evaluated by analyzing claims for cold injury. Five hundred ten claims filed in 1983 from 23 states participating in the Bureau of Labor Statistics Supplementary Data System and an additional 147 claims filed with the Division of Safety and Hygiene of the Industrial Commission of Ohio from Jan 1, 1984, to June 30, 1985, were examined. As expected, the number of injuries per winter day increased as temperature decreased and wind speed increased. The rate of injury began to increase when temperatures fell below 10 degrees F and wind speeds exceeded 10 mph. These weather conditions were milder than previously published cold hazard charts suggest. Frostbite injuries of the lower extremities occurred at milder temperatures, required more lost workdays, and were more costly than cold injuries to the head and face or to the upper extremities. Industries with the highest rates of injury included agriculture, oil and gas extraction, trucking and warehousing, protective services, and interurban transportation. Injuries during nonwinter months involved the processing, distribution, and preparation of food. Vehicle breakdown or contact with water, gasoline, alcohol, or cold water were noted as contributing factors on many of the compensation claims. This probe suggests that claims for workers' compensation adequately reflect the expected association of environmental factors and the occurrence of cold injury.

Absenteeism↗

Phytophotodermatitis from celery among grocery store workers.

We detected 19 cases of phytophotodermatitis during a cross-sectional epidemiological investigation of two Oregon grocery stores that were part of the same supermarket chain. Outdoor sunlight exposure during the workshift and tanning salon use were identified as risk factors; the most severe cutaneous reactions tended to occur among tanning salon users. Although both stores carried the same brands and varieties of produce, all 19 cases occurred among employees of one store, which had held a celery sale coincident with the outbreak, resulting in a quadrupling of the usual volume of celery sold. We found elevated psoralen levels in two of three celery samples obtained from the affected store; cutaneous provocation tests with trimmed surfaces of these celery samples produced phototoxic reactions. Preliminary experiments with one brand of celery have demonstrated psoralen levels as high as 25 micrograms/cm2 of trimmed surface. These observations suggest that clinical phytophotodermatitis among grocery store workers may be caused by healthy celery and results from a complex interaction of exposure variables, including ultraviolet radiation from tanning salon use, frequency of handling celery, celery brand, and sporadic elevation of psoralen content from environmental stresses.

Cross-Sectional Studies↗

Allergic contact dermatitis from a nonbisphenol A epoxy in a graphite fiber reinforced epoxy laminate.

An employee of the Composites Division of an aircraft engine manufacturing firm developed dermatitis associated with the handling of a graphite fiber reinforced epoxy laminate (epoxy prepreg). Patch test investigation demonstrated that the responsible causal agent was the nonbisphenol A epoxy binder, 4-glycidyloxy-N, N-diglycidylaniline. A patch test with bisphenol A epoxy from a standard patch test screening series was negative. Subsequent interviews with employees of the Composites Division suggested that a relative lack of awareness of the cutaneous hazards of fiber reinforced epoxy laminates, compared with liquid epoxy resin systems, may be an important risk factor for allergic sensitization to these composite materials.

Adult↗

The contact urticaria syndrome.

Contact urticaria may occur following contact of the skin or mucous membranes with a large number of diverse substances. When localized angioedematous reactions of the eyes or oropharynx are caused by proteinaceous substances, the distinction between contact urticaria and common inhalant or food allergies is subtle. The time course of the reaction, negative controls, or occurrence of generalized symptoms do not constitute unequivocal evidence of immunologic contact urticaria, and confirmation by RAST or passive transfer testing is required. Clinical symptoms range from mild, localized erythema to generalized anaphylaxis. When contact urticaria becomes superimposed on eczematous skin, immediate reactions that resemble eczema more than urticaria may occur. Dermatologists must increase their awareness of these clinical reactions and evaluate the external environment when searching for causes of localized urticarial reactions.

Biomechanical Phenomena↗

Delayed hypersensitivity to a corticosteroid suspension containing methylprednisolone. Two cases of conjunctival inflammation after retrobulbar injection.

Two patients with chronic iridocyclitis had a delayed hypersensitivity reaction, characterized by severe conjunctival inflammation, after retrobulbar injections with a commercial suspension of methylprednisolone acetate. Although patch test reactions to methylprednisolone at enhanced concentrations were negative, delayed hypersensitivity could be easily demonstrated by intradermal testing with this corticosteroid. Both patients also had concomitant delayed hypersensitivity to a proprietary preservative (myristyl gamma-picolinium chloride) in the commercial corticosteroid suspension, which was confirmed by intradermal testing. These observations (negative patch test reactions, positive intradermal test reactions) suggest that the route of administration may be an important determinant of antigenic hapten-protein complex formation and subsequent delayed hypersensitivity responses involving cutaneous or mucocutaneous tissue.

Adult↗

Allergic contact dermatitis from rosin used as soldering flux.

Two cases of allergic contact dermatitis from soldering fluxes are reported. Both were caused by rosin (colophony). One case was confirmed by a positive patch test to rosin purchased from a commercial European patch test supplier. The other could be confirmed only by a positive patch test to the specific rosin used to flux the solder; repeated patch tests to rosin purchased from the same European supplier were negative. Dermatitis from soldering fluxes is reviewed.

Adult↗

Allergic contact dermatitis from anaerobic acrylic sealants.

Three patients employed in electronic assembly operations had allergic contact dermatitis to polyethylene glycol (PEG) dimethacrylate, found in an anaerobic sealant. Clinical features in all three cases consisted of eczema localized predominantly on the distal parts of the fingers and the palmar aspects of fingertips; onycholysis developed in one patient. No cross reactions to methyl methacrylate were observed on patch testing. Guinea pig maximization testing with both the commercially available sealant and the active resin demonstrated that PEG dimethacrylate is a moderate skin sensitizer.

Acrylic Resins↗