Adverse reactions following exposure to latex products may be categorized as (1) irritant contact dermatitis (not associated with allergy), (2) cell-mediated delayed hypersensitivity reactions (allergic contact dermatitis), and (3) IgE-mediated immediate hypersensitivity reactions (urticaria, angioedema, allergic rhinoconjunctivitis, asthma, and generalized anaphylactic shock).5,7,9,11,17
Irritant Contact Dermatitis
The most common adverse reaction to latex products, specifically to latex gloves, is irritant contact dermatitis (ICD). It is characterized by dry, cracked, itchy, irritated areas of the skin (usually of the hands). The time of onset is gradual (over several days) as a result abrasion and maceration from donning and removing gloves, repeated hand washing and drying, incomplete hand drying, the use of cleaners and sanitizers, and exposure to other workplace products and chemicals.5,7,9,18
Allergic Contact Dermatitis
Allergic contact dermatitis (ACD) is caused primarily by the accelerators, promoters, and antioxidants that are added to natural rubber latex during harvesting, processing, or manufacturing.5,7-10,12,18 It is characterized by a papular, pruritic (itchy) rash (Figure 1); which usually begins 24 to 48 hours after contact with offending products and may progress to oozing vesicles and blisters and spread to areas of skin untouched by latex.12,19,20 ACD may be the first sign that more serious reactions could occur with continued exposure.
IgE-mediated Immediate Hypersensitivity Reactions
The risk of progression from ACD to more serious allergic reactions is unknown. At least some of the patients, who initially develop ACD with repeated exposure to latex may experience acute urticariaconsidered to be a transitional stage between ACD and IgE-mediated immediate hypersensitivity reactions (Figure 2). Symptoms usually occur within 60 minutes of exposure to a latex product and are characterized by itching, redness, and a wheal and flare reaction at the site of contact.21
Deposits of latex proteins on mucosal surfaces of the eyes and upper respiratory tract can lead to allergic rhinoconjunctivitis. Clinical signs and symptoms include watery eyes, nasal congestion, sneezing, rhinorrhea, and an itching sensation of the oropharyngeal mucosa. If sufficient aeroallergens penetrate below the level of the glottis, the allergic response progresses to acute bronchospasm.22 It is estimated that 2.5% of healthcare workers are susceptible to latex aeroallergen-induced acute asthma.23
When latex proteins interact with IgE antibodies on mast cells and basophiles, a massive release of histamine and other substances result in generalized anaphylactic shock. Early signs and symptoms include weakness, dizziness, flushing and urticaria. It progresses rapidly and sequentially to laryngeal edema (resulting in stridor) and bronchospasm (resulting in wheezing); followed by hypotension, tachycardia, and vascular collapse as a result of decreased systemic vascular resistance (Figure 4).17,24