Selected topics related to occupational exposures. Part III. Occupational dermatology

Occupational skin disorders are very common and are a surprisingly frequent cause of lost work time. Failure to suspect an occupational cause can lead to repeated treatment failure and needlessly prolong patient misery and frustration. Primary care providers play a key role in recognizing possible occupational causes and arranging appropriate education, preventive measures, and treatment. Occupational skin conditions often occur in nonindustrial settings in workers such as hairdressers, health care personnel, and food handlers. Irritant contact dermatitis is by far the most prevalent occupational skin condition and is emphasized in this article. Allergic contact dermatitis, infections, skin cancers, and acneform eruptions may also have significant occupational associations. We will present criteria that suggest on occupational exposure, list common offending agents, and review the clinical presentations and relevant pathophysiology. We provide guidance on a directed history and physical examination and suggest when diagnostic testing is most likely to have value. Finally we outline preventive measures such as contact avoidance, barrier creams, and protective gloves and address therapy and indications for referral.     

Evaluating work relevancy of dermatitis. Basic cognitive skills

Occupational contact dermatitis is recognized by its history, appearance, and location. The leading causes of work related skin disease are chemical agents that include primary irritants, allergic- and photosensitizers, and systemic intoxicants that are absorbed through the skin. Recognized guidelines must be used to determine work relevancy: either the skin eruption if related directly to a specific workplace exposure or the work environment caused an aggravating effect on a preexisting non-work related skin disorder. The health care provider's role in industry is not only to examine, diagnose, and treat an injured person's dermatitis, but to identify the cause of the skin eruption and make recommendations for protective measures to prevent recurrent morbidity.     

Occupational skin diseases

Primary care physicians will likely see a wide variety of occupational skin diseases in their practices, including allergic contact dermatitis, irritant contact dermatitis, contact urticaria, a variety of infectious diseases, and skin cancers. The ideal role of a medical practitioner involved in occupational dermatology is not only to diagnose and treat patients, but also to determine the cause of the occupational skin disease and to make recommendations for its prevention. Making the diagnosis and offering treatment, determining the cause, and recommending measures can be difficult undertakings.     

Allergic reactions to latex among health-care workers.

With the emergence of the acquired immunodeficiency syndrome (AIDS) epidemic and the practice of protecting health-care workers from all body fluids, the use of rubber gloves has increased, as has occupational allergy to latex among health-care workers. During 1991, 49 Mayo Medical Center employees sought assessment and treatment of rhinitis, conjunctivitis, contact urticaria, contact dermatitis, asthma, or eczema thought to be related to exposure to latex. Most of these persons had a history of atopy and worked in areas where rubber gloves were used and changed frequently. Of the 49 subjects, 34 had positive results of skin tests to latex products, and the sera from 19 of 35 persons tested contained increased latex-specific IgE antibodies. Employees with sensitivity to latex (and co-workers in the immediate areas) should use vinyl gloves and should notify their own health-care providers of their sensitization. Changes in job assignment may be necessary for some persons.     

Contact dermatitis: diagnosis and management

Contact dermatitis accounts for 85-90% of all occupational skin diseases and, as a frequent cause of hand dermatitis, it can lead to unemployment and permanent disability. This article examines the two main types of contact dermatitis, their diagnosis and treatment.     

Laboratory animal allergy: an occupational hazard.

Laboratory animal allergy is a relatively common work-related condition occurring in an estimated one-third of laboratory animal workers. More than 10% of these workers develop occupational asthma. Sensitization often occurs in the first 3 years of employment. Risk factors include a personal or family history of atopy, other preexisting non-work-related allergies, and a significant exposure to laboratory animals. Inhalation is the most common route of exposure, followed by skin and eye exposures. Preplacement testing and regular health surveillance screening may be used by institutions employing laboratory animal workers to identify, monitor, and prevent allergies and disease in these workers. Intervention and prevention techniques (i.e., engineering, administrative, and work practice controls and personal protective equipment) are key to controlling and preventing allergy symptoms and occupational asthma. Occupational health professionals play an important role in the early identification of at-risk and affected employees, and can render the necessary treatment, referrals, education, and recommendations to prevent debilitating illness.     

Severe dermatitis with loss of epidermal Langerhans cells in human and mouse zinc deficiency

Zinc deficiency can be an inherited disorder, in which case it is known as acrodermatitis enteropathica (AE), or an acquired disorder caused by low dietary intake of zinc. Even though zinc deficiency diminishes cellular and humoral immunity, patients develop immunostimulating skin inflammation. Here, we have demonstrated that despite diminished allergic contact dermatitis in mice fed a zinc-deficient (ZD) diet, irritant contact dermatitis (ICD) in these mice was more severe and prolonged than that in controls. Further, histological examination of ICD lesions in ZD mice revealed subcorneal vacuolization and epidermal pallor, histological features of AE. Consistent with the fact that ATP release from chemically injured keratinocytes serves as a causative mediator of ICD, we found that the severe ICD response in ZD mice was attenuated by local injection of soluble nucleoside triphosphate diphosphohydrolase. In addition, skin tissue from ZD mice with ICD showed increased levels of ATP, as did cultured wild-type keratinocytes treated with chemical irritants and the zinc-chelating reagent TPEN. Interestingly, numbers of epidermal Langerhans cells (LCs), which play a protective role against ATP-mediated inflammatory signals, were decreased in ZD mice as well as samples from ZD patients. These findings suggest that upon exposure to irritants, aberrant ATP release from keratinocytes and impaired LC-dependent hydrolysis of nucleotides may be important in the pathogenesis of AE.     

Treating the patient with multiple cosmetic product allergies. A problem-oriented approach to sensitive skin

Treating patients with multiple allergies to cosmetic products is a difficult proposition. Many of these patients may simply be experiencing irritant contact dermatitis. Others may have defective barrier function caused by a dermatitis that requires treatment. And some patients with sensitive skin need to exercise care in choosing which products they use on their skin. For many of these patients, products with the fewest ingredients work best because they contain the least or no sensitizers, irritants, or cutaneous sensory stimulants.     

Needle stick injuries: nurses at risk

According to the Centers for Disease Control and Prevention (CDC), American health care workers suffer between 600,000 and 1 million needle sticks and other sharps injuries every year. Needle stick injuries are considered to be widely underreported. Eighty percent of blood contacts occur through needle sticks, making this the most common cause of health care work-related exposure to bloodborne pathogens. More than 20 pathogens can be transmitted through small amounts of blood. These include HIV, hepatitis B and C, other forms of hepatitis, syphilis, Rocky Mountain spotted fever, varicellazoster, and malaria. Hepatitis B is the most common infectious disease transmitted through work-related exposure to blood. The CDC reports that 5,100 health care workers become infected with hepatitis B each year through job-related blood contact. There have been 54 documented cases of HIV seroconversions among U.S. health care workers resulting from occupational exposures. Needle stick injuries caused by hollow-bore needles accounted for 86 percent of all reported occupational HIV exposures. Nurses make up 24 percent of the cases of HIV infection among health care workers known or thought to have been infected on the job. Research shows that 83 percent of these injuries can be prevented--most through the use of needles with safety features or needleless systems. According to the American Hospital Association, one case of serious infection by bloodborne pathogen can result in expenditures of $1 million or more for testing, follow-up, time lost from work, and disability payments. The cost of follow-up for a high-risk exposure is almost $3,000 per needle stick injury, even when no infection occurs. Safe needle devices cost about 28 cents more than standard devices.     

Latex glove allergy--dilemma for health care workers. An overview.

1. The prevalence of latex allergy in health care workers is estimated to be between 10% and 17%. 2. Reactions from wearing latex gloves can include irritant contact dermatitis, allergic contact dermatitis, and contact urticaria from latex proteins. 3. Individuals with a history of atopy, multiple surgeries early in life (particularly with bladder catheterization), or allergies to certain foods are considered at risk of latex allergy. 4. An early intervention protocol and documentation forms are offered for occupational health nurses faced with assessing potentially latex allergic employees.     

Chronic obstructive pulmonary disease. Reversing airflow obstruction from chronic bronchitis and emphysema

Chronic obstructive pulmonary disease (COPD) describes a group of disorders that cause obstruction to expiratory airflow. COPD should be suspected in a patient who has cough, sputum production, wheezing, and/or inappropriate dyspnea on exertion in the setting of prolonged exposure to cigarette smoke. With smoking cessation, avoidance of occupational and other bronchial irritants, and use of bronchodilators, antibiotics, and long-term oxygen when appropriate, the patient can minimize limitations on activity and complications.     

Norwegian-type scabies mimicking contact dermatitis in an immunosuppressed patient

Patients taking immunosuppressive drugs are susceptible to various forms of infection, including dermatologic disease. Recently, atypical manifestations of scabies have been reported in such patients. In the case reported here, a 26-year-old woman who had had a renal transplant and was taking immunosuppressive drugs had a pruritic rash on the back that closely resembled contact dermatitis. However, skin scrapings from the involved areas and punch biopsy specimen of the back showed live scabies mites. The pruritus was relieved and the skin lesions disappeared within ten days of treatment with scabicides. We believe that current widespread use of immunosuppressive agents may result in more cases of atypical forms of scabies. Therefore, physicians who deal with immunosuppressed patients should be aware of this possibility.     

Clinical picture, diagnosis, and prevention of occupational allergic diseases

The paper is concerned with a clinical picture of various types of occupational allergic diseases caused by exposure to occupational allergens. In view of a clinical course and pathogenesis of these diseases a set of diagnostic methods was developed, including allergy-oriented examination of patients using skin, endonasal and inhalation tests. Early diagnosis of allergic diseases and interruption of the workers' contact with occupational substances of allergic and irritant action are recommended for the prevention of severe allergic lesions of the respiratory organs and skin. The use of special protective ointments and pastes is indicated in skin diseases.     

Asthma caused by bromelain: an occupational allergy

Bromelains consist of a group of proteolytic enzymes of Bromeliaceae. They are commonly used in pharmaceutical industries, food production and in diagnostic laboratories. Bromelains are known to cause IgE-mediated reactions of both the immediate type and the 'late phase reaction of immediate type reaction' with predominantly respiratory symptoms. We report four cases of occupational allergy to bromelain in workers of a blood grouping laboratory. These observations prompted us to investigate the sensitization rate to bromelain in all workers of the particular diagnostic laboratory who had contact with bromelain. These results were compared with those obtained from healthy, randomly selected individuals without evident bromelain exposure. Our findings indicate that (i) bromelain is a strong sensitizer, (ii) sensitization usually occurs due to inhalation and not to ingestion, (iii) bromelain allergy is occupationally acquired, and adequate precautions are necessary. We can further state that (iv) skin testing with relatively pure allergens such as isolated proteases like bromelain may induce systemic reactions, even at very high dilutions.     

Allergic contact dermatitis. When to suspect it and what to do

Allergic contact dermatitis is a common problem that can affect persons of all ages and in any state of health. A high index of suspicion and careful follow-through with patch testing and investigative work are needed to establish the diagnosis. Recognition of sources of exposure to the allergen and of important cross-reacting substances is the key to prevention of recurrences.     

Preoperative skin testing of materials used in surgical procedures

Postoperative skin complications increase health care costs and cause patient suffering. In the OR, patients are exposed to materials with adhesive substances that have the potential to cause allergic or toxic effects on the skin. Intraoperatively and postoperatively, these reactions can result in skin complications. The objective of this study was to investigate the incidence of skin reactions in connection with the application of different materials. Skin reactions after preoperative skin testing occurred in 3% to 50% of patients with atopic or contact eczema, allergy, or asthma in their medical history. AORN J 77 (April 2003) 762-771.     

EXPERIMENTAL STUDIES ON THE ETIOLOGY OF TYPHUS FEVER : VI. SKIN LESIONS IN EXPERIMENTAL TYPHUS FEVER OF GUINEA PIGS.

The skin of guinea pigs in which the virus of typhus fever is propagated, when mildly irritated in advance of the febrile reaction, shows a characteristic exanthem during the height of the experimental disease. More drastic methods of irritation, however, cause a dermatitis which obscures the rash but produce in the corium more marked specific histopathological changes. The exanthem may aid the study of the specific incitant of typhus fever in the lesions.     

A guide to the diagnosis and treatment of occupational asthma

Occupational asthma is the most prevalent form of occupational lung disease in industrialized nations. As increasing numbers of new chemicals are produced and new manufacturing processes are introduced, the variety of environments in which individuals may become exposed to respiratory sensitizers and irritants makes diagnosing and treating this illness even more challenging. In addition to adverse pulmonary effects, the diagnosis of occupational asthma may bring with it negative social and financial implications that may ultimately affect the patient's quality of life. For this reason, it is important for clinicians to recognize work-related respiratory symptoms early on in their course, maintain a high clinical suspicion for an occupational cause in the diagnostic work-up of asthma, and have a high degree of certainty in the diagnosis. While a number of classification schemes have been proposed to simplify the diagnostic approach to occupational asthma, the inciting factors typically involve sensitization (often by an IgE mechanism), direct airway inflammation, various pharmacologic responses, or irritant reflex pathways. Clinicians must first document the presence of asthma, then establish a relationship between asthma and the work-place. The occupational history is the key diagnostic tool, and clinical suspicions may be evaluated further by serial peak expiratory flow measurements, nonspecific hypersensitivity challenges with histamine or methacholine, collaboration with industrial/occupational hygienists to obtain workplace exposure measurements, and specific challenge testing at tertiary referral centers providing specialized laboratories. Removal from the inciting exposure is the mainstay of therapy, and pharmacologic treatment of patients with occupational asthma is similar to the treatment of patients with other forms of asthma.