Winter 2005, Vol.11, No. 4

Dermatitis: Is It Irritation Or Allergy?

This article originally appeared in the Winter 2005 issue of The ALERT NEWSLETTER, Vol.11, No. 4

Contributed by James Taylor, MD

1. Which types of dermatitis are related to latex allergy?

Latex Allergy:
Latex allergy is an IgE-mediated, immediate-type hypersensitivity reaction to one or more proteins present in raw or uncured natural rubber latex (NRL). Predisposing risk factors include hand eczema, allergic rhinitis, allergic conjunctivitis, or asthma in individuals who frequently wear NRL gloves; mucosal exposure to NRL; and multiple surgical procedures.

The spectrum of clinical signs ranges from contact urticaria, generalized urticaria, allergic rhinitis, allergic conjunctivitis, angioedema, and asthma to anaphylaxis. The majority of cases involve reactions from wearing NRL gloves or being examined by individuals wearing NRL gloves. Reactions from other medical and non-medical NRL devices have occurred and are red flags for the diagnosis; these include balloons, rubber bands, condoms, vibrators, dental dams, anesthesia equipment, and toys for animals or children.

The route of exposure to NRL proteins is important; and includes direct contact with intact or inflamed skin and mucosal exposure, such as inhalation of powder from NRL gloves, especially in medical facilities and operating rooms. Most immediate-type NRL reactions result from exposure to dipped NRL products (gloves, condoms, balloons, and tourniquets). Dry molded rubber products (syringes, plungers, vial stoppers and baby nipples) contain lower residual protein levels or have less easily extracted proteins than do dipped products that are produced from NRL.

Irritation:
Irritant contact dermatitis is probably the most frequent adverse glove reaction, especially among those with occupational exposure to latex gloves. This non-immunologic cutaneous response manifests as dry, crusted, fissuring lesions on glove-exposed areas. Heese et al, found that, of 432 latex glove intolerant reactions, irritation occurred in 40%, type I latex allergy in 33.1%, type IV allergic contact dermatitis in 20.4%, and both type I and type IV reactions in 6.5%. Irritant reactions occur especially in atopic patients, but anyone who is exposed to an irritant in sufficient concentration for a long enough period of time will develop dermatitis. The frequent use of disinfectants and hand sanitizers, or the failure to rinse and dry hands properly after washing, may result in maceration of the skin and irritant dermatitis. During glove usage, sweating of the skin under occlusion, mechanical friction from ill-fitting gloves, glove powder, and chemical glove additives may also provoke and exacerbate irritant reactions, which may clinically mimic glove allergies. Irritation is probably an important cofactor in the induction of allergic contact dermatitis and contact urticaria. By altering stratum corneum function, irritation may reduce the barrier function of the skin and allow penetration of chemical accelerators and antioxidants or NRL proteins.

Allergic Contact Dermatitis:
In sensitized individuals, allergic contact allergy to rubber gloves is caused by a type IV, T cell-mediated, delayed response, and typically occurs 48 to 96 hours after exposure. Contact allergy should be suspected in any patient who wears rubber gloves and has a diffuse or patchy eczema on the dorsal surface of the hands or forearms. A pattern, with sharp demarcation at the wrists, would be expected, but many have nonspecific patterns of hand eczema in which the diagnosis could not have been made without routine patch testing. Correctly identifying the underlying mechanism of a glove-related reaction can be difficult because in some individuals symptoms of both type IV and type I reactions may be present.

Even when the patient is not allergic to rubber, gloves may make a pre-existing hand dermatitis worse from occlusion and maceration, a clinical picture mimicking allergic reaction to gloves. Major contact allergens are the accelerators (thiurams, carbamates, thiazoles, etc) and antioxidants (paraphenylenediamine, etc) added during glove production. NRL itself has been reported to be the cause of allergic contact dermatitis in users of natural rubber gloves. Type IV reactions can begin as early as 8 hours or as long as 5 days after exposure. Clinically, the acute phase is characterized by vesicular skin lesions, which, with continued exposure, will develop a crusted, thickened appearance.

2. How are the different types of dermatitis diagnosed?

Latex Allergy:
Diagnosis of NRL allergy is strongly suggested by obtaining a history of angioedema of the lips when inflating balloons; and/or itching, burning, urticaria, or anaphylaxis when donning gloves; undergoing surgical, medical, and dental procedures; or following exposure to condoms or other NRL devices. Diagnosis is confirmed by either a positive wear or use test with NRL gloves, a positive intracutaneous prick test to NRL (there still is no FDA-approved NRL prick test antigen), or a positive serum RAST to NRL.

Irritation: Diagnosis of irritant contact dermatitis is based on the history and clinical exam and exclusion of other causes, especially allergic contact dermatitis

Allergic Contact Dermatitis (ACD):
ACD is diagnosed by the history, clinical evaluation of the dermatitis, and patch testing. The patch test is the gold standard for the diagnosis of ACD. The proper performance and interpretation of this bioassay require considerable experience. Because the procedure is subject to patient variability and observer error, the technique has been standardized by various national and international bodies.

First, the allergen is diluted in petrolatum or water to a concentration that does not produce active sensitization or irritation. A widely used patch test system consists of strips of paper tape onto which are fixed 8-mm-diameter aluminum disks (Finn Chambers on Scanpore tape). A small amount of allergen is placed within these disks, covering slightly more than one half of its diameter.

The other method utilizes the T.R.U.E. test, or thin-layer rapid-use epicutaneous test. The T.R.U.E. test contains 23 “pre-loaded” allergens, which are crystallized, micronized, or emulsified into gels, and which are affixed to paper tape.

With both systems, the tests are applied to the upper or mid back, which must be free of dermatitis. The patches are left in place and kept dry. When removed at 48 hours, the first reading is generally performed after 20 to 30 minutes, which allows time for pressure erythema to resolve. It is important to perform a second reading, usually between four and seven days after the patches are initially applied. Patch testing is best done by physicians familiar with the intricacies of the procedure, who are also trained to advise patients about allergen substitution, relevance of the test, and prognosis. The reading and interpretation of relevance are as important as performance of the test. Any reaction must be evaluated in regard to the individual patient. Thus, when an allergen is found to be positive, it cannot always be assumed to be the cause of the current ACD. Relevance is determined by correlating the patch test results with chemicals, products, and processes encountered in the environment.

3. How are the different types of dermatitis treated?

Latex allergy: NRL avoidance and substitution is imperative. Because many patients with NRL allergy are atopic with hand eczema, immediate allergic symptoms, or both, the most important issues for physicians are accurate diagnosis, appropriate treatment, and counseling. Prevention and control of NRL allergy includes latex avoidance in health-care settings for affected workers and patients. Substitute synthetic non-NRL gloves should be available; and low-allergen NRL gloves or non-NRL gloves may be needed by coworkers to accommodate those with NRL allergy. Selected substitute gloves are listed in the Table below. (The rubber accelerators are listed in case the patient has concomitant allergic contact dermatitis to rubber). Lists of gloves and other non-NRL devices have also been published by the American Latex Allergy Association (A.L.E.R.T. Inc.).

Irritant and Allergic Contact Dermatitis:
Allergen avoidance and substitution:
Most cases of contact dermatitis can be effectively treated and controlled once the offending irritant or allergen is identified and eliminated. Identifying hidden sources of allergens is important, and patients are given exposure lists for positive patch tests, which identify various names of the allergen, cross-reacting substances, lists of potential products and processes containing the allergen, and non-sensitizing substitutes.

Topical Therapy:

  • In the acute vesicular stage, cool wet soaks for 15 minutes, two to three times daily with commercial preparation of Burows solution (aluminum subacetate).

  • A lotion of camphor, menthol and hydrocortisone (Sarnol HC) is soothing, drying, and antipruritic.

  • Pramoxine, a topical anesthetic in a lotion base (Prax), may also relieve pruritus.

  • In the subacute and chronic stages of contact dermatitis, an emollient lotion (Eucerin) or ointment (Aquaphor) may be applied to moist skin after bathing for lubrication.

  • Corticosteroid creams and ointments are effective anti-inflammatory agents in subacute and chronic contact dermatitis. Hydrocortisone is sometimes effective topically in a 1 % concentration. The higher-potency fluorinated corticosteroids act more rapidly, but should be used with discretion and are available by prescription. Frequent and prolonged use in fold areas may cause atrophy, telangiectasia, and their use on the face may cause steroid rosacea.

  • Bath PUVA may be effective for contact dermatitis of the palms of the hands and soles of the feet.

Systemic Therapy:
Intense itching may be relieved by sedating antihistamines, such as diphenhydramine hydrochloride (Benadryl), hydroxyzine hydrochloride (Atarax), or doxepin hydrochloride (Sinequan), administered at night. Most cases of ACD are effectively managed without the use of systemic corticosteroids. However, short courses of systemic corticosteroids are indicated in severe vesiculobullous eruptions of the hands and feet or face, or severe disseminated ACD. Attempts at desensitization have generally been unsuccessful. Secondary infection occasionally arises as a complication of ACD, and systemic antibiotics may be indicated.

Chronic Dermatitis:
Reasons for persistence of ACD include: Unidentified sources of allergens or irritants at home or at work, exposure to cross-reacting allergens, presence of underlying endogenous (e.g., atopic) eczema, and adverse reactions to therapy. In the case of hand dermatitis, practical management must include protective measures, as well as the use of topical corticosteroids and lubrication. The use of vinyl gloves with cotton liners to avoid the accumulation of moisture that often occurs during activities involving exposure to household or other irritants and foods (e.g., peeling or chopping of fruits or vegetables) may be helpful. In the workplace, verify that gloves are safe to use around machinery before recommending them. Protective devices themselves may introduce new allergic or irritant hazards in the form of rubber in gloves and solvents in waterless cleansers.

Selected Synthetic Gloves (With Accelerators*) For Patients With Type I Latex Allergy
(*Important to verify as this information may change)

Glove Accelerators
Polyisoprene gloves Carbamates or Thiurams/Thiazoles
Vinyl gloves No accelerators, but allergic contact dermatitis has rarely been reported from vinyl glove additives
Nitrile gloves Carbamates/Thiazoles, but N-Dex Free gloves have no accelerators
Neoprene gloves:
Dermaprene exam
Dermaprene Ultra Surgical
Biogel Neoprene
Duraprene synthetic/Neoln PF
Thiourea
No accelerators
Diphenyl Guanidine
Carbamates
Polyurethane gloves:
Sensicare Advantix
No accelerators
Block Polymer gloves:
Elastylite
Elastylon
Elastyplus
No accelerators



4. What is the significance of each type of dermatitis?
It is important to be aware that the same individual may have more than one diagnosis. Patients with latex allergy may also have an associated irritant and allergic contact dermatitis. Allergic contact dermatitis may be caused by chemicals in gloves as well as other substances in the environment, including reactions to topical medications. It is also important to realize many skin disorders affect the hands, including pressure urticaria, atopic eczema, tinea manum (superficial fungal infection) and psoriasis, to name just a few. Anyone with hand dermatitis who wears rubber gloves should be evaluated for latex allergy and allergic contact dermatitis.

Adult atopic eczema often is localized to the hands and may co-exist with latex allergy, irritation, and allergic contact dermatitis, and may account for persistence of dermatitis in some cases. Patch testing with more extensive panels, including patient topicals, may be warranted in some cases. Signs and symptoms of latex allergy may be masked by concomitant atopic, irritant and/or allergic dermatitis. In contrast to the other dermatological disorders, latex allergy may be associated with serious systemic reactions. Accurate diagnosis and management is critical to ideal outcomes and avoidance of persistent reactions.