Irritable reactions

Eye and Skin Contact. Some nickel salts and aqueous solutions of these salts, eg, the sulfate and chloride, may cause a primary irritant reaction of the eye and skin. The most common effect of dermal exposure to nickel is allergic contact dermatitis. Nickel dermatitis may occur in sensitized individuals following close and prolonged contact with nickel-containing solutions or metallic objects such as jewelry, particularly pierced earrings. It is estimated that 8—15% of the female human population and 0.2—2% of the male human population is nickel-sensitized (125). 

Health and Safety. FEMA has examined cinnamaldehyde and estabhshed its GRAS status (No. 2286). The material has been used in some fragrance compositions, but RJEM (34) has noted its potential for sensiti2ation and limited the use in perfumes for skin contact at 1% in the formula. Eugenol and limonene have been used in conjunction with cinnamaldehyde as quenchers to neutrali2e the irritation reaction that some individuals have toward this aldehyde. 

Toxic Reactions of the Skin Irritation is the most common reaction of the skin. Skin irritation is usually a local inflammatory reaction. The most common skin irritants are solvents dehydrating, oxidizing, or reducing compounds and cosmetic compounds. Acids and alkalies are common irritants. Irritation reactions can be divided into acute irritation and corrosion. Necrosis of the surface of the skin is typical for corrosion. Acids and alkalies also cause chemical burns. Phenols, organotin compounds, hydrogen fluoride, and yellow phosphorus may cause serious burns. Phenol also causes local anesthesia, in fact it has been used as a local anesthetic in minor ear operations such as puncture of the tympanous membrane in cases of otitis. ... 

PHARMACOLOGICAL ACTIVITIES AND CLINICAL TRIALS Allergenic activity. Oleoresin powder, administered externally to adults, was active. Reactions to patch test occurred most commonly in patients who were regularly exposed to the substance, or who already had dermatitis on the fingertips. Previously unexposed patients had few reactions (i.e., no irritant reactions... 

Clinicians should remain alert to signs or symptoms signaling possible esophageal irritation reaction (dysphagia, retrosternal pain, or heartburn)... 

Eye and Skin Contact. Some nickel salts and aqueous solutions of these salts, e.g.. the sulfate and chloride, may cause a primary irritant reaction of the eye and skin. The most common effect of dermal exposure to nickel is allergic contact dermatitis. 

Local skin irritation reactions occasionally are reported with the use of chlor-hexidine. Long-term experience demonstrated an extremely low incidence of sensitization reactions. There have been isolated reports of generation allergic reactions, and in the most severe cases shock has occurred (Kimura et al. 1994). 

Podophyllotoxin and its derivatives are active cytotoxic agents with specific affinity for the microtubule protein of the mitotic spindle. Normal assembly of the spindle is prevented, and epidermal mitoses are arrested in metaphase. A 25% concentration of podophyllum resin in compound tincture of benzoin is recommended for the treatment of condyloma acuminatum. Application should be restricted to wart tissue only, to limit the total amount of medication used and to prevent severe erosive changes in adjacent tissue. In treating cases of large condylomas, it is advisable to limit application to sections of the affected area to minimize systemic absorption. The patient is instructed to wash off the preparation 2-3 hours after the initial application, since the irritant reaction is variable. Depending on the individual patient s reaction, this period can be extended to 6-8 hours on subsequent applications. If three to five applications have not resulted in significant resolution, other methods of treatment should be considered. 

Further, the EMP has allowed studies of the water profile over the skin cross section30,31 the physiological changes at irritant reactions 12 14,44 6 and psoriasis.32 A comprehensive overview of the EMP application is given in two overview papers 49,50... 

Lindberg, M., Forslind, B., and Roomans, G.M., Elemental changes at irritant reactions due to chromate and nickel in guinea-pig epidermis, Scanning Electron Microsc., 3, 1243, 1983. 

Willis, C. and Lindberg, M., Understanding the irritative reaction, in Forslind, B. and Lindberg, M., Eds., Skin, Hair, and Nails. Structure and Function, New York-Basel, Marcel Dekker Inc., 2004, 233. 

The SLS is frequently used to induce experimental irritant dermatitis. The reaction is characterized by erythema, increased TEWL, and scaliness. Susceptibility to SLS irritation can be used as an assay for the prevention of irritant reaction by moisturizers.23-25... 

Direct irritation may thus be dehned as an adverse effect of chemicals directly applied to the skin that does not involve prior sensitization and thus initiation by an immune mechanism. Irritation is usually assessed by a local inflammatory response characterized by erythema (redness) and/or edema (swelling). Other responses may be present that do not elicit inflammation such as an increase in skin thickness. Irritant reactions may be classified as acute, cumulative, traumatic, or pustular. However, two classifications are generally used by toxicologists. Acute irritation is a local response of the skin usually caused by a single agent that induces a reversible inflammatory response. Cumulative irritation occurs after repeated exposures to the same compound and is the most common type of irritant dermatitis. 

The formaldehyde concentration in patch-testing, which has been lowered to 1% in the standard series in recent years, has been studied in a comparison of concentrations of 1% and 2% in 3734 consecutively patch-tested patients (11). Since there was no significant difference between 1 and 2% formaldehyde with respect to the frequency of positive patch test reactions, while there were more irritant reactions with 2%, a 1% patch test concentration can still be recommended. 

The irritable reactions manifested by protoplasm and living things to the effects of these external agents will now be considered briefly. 

Ten pages have been added to Chapter V on Cytology. Under Protoplasm and its Properties, six pages have been written on the subject of Irritability and Irritable Reactions. Under Non-Pro toplasmic Cell Contents several additional commercial starches are discussed and two original plates on starch grains added. Additional cuts on Collenchyma, Stone Cells, Sclerenchyma Fibers, Trichomes and Fibrovascular Bundles have been inserted in Chapter VI. 

Lahti A, Pylvanen V, Hannuksels M. Immediate irritant reactions to benzoic acid are enhanced in washed skin areas. Contact Dermatitis 1996 35(1) 51. 

Thus far, most in vitro irritation methods, including Skintex, have relied heavily on the vast Draize rabbit skin database for validation. As previously discussed, the discrepancies in the information generated by the Draize system raise questions about the applicability of this information to irritation reactions in man. 

Tolnaftate is ineffective when administered by oral and parenteral routes (13). Therefore, it is administered only by topical route, and no reports on its pharmacokinetics and systemic metabolism have been documented. The LD50 of this drug in different animals is shown in Table 6 (4). In dogs, no toxicity was observed when a massive dose (14 g/kg) was administered orally, and in rabbits, no sensitization or irritation reaction was observed when 1% (w/v) tolnaftate solution was applied topically for 20-90 days (14). Results of this study also revealed that tolnaftate is not absorbed percutaneously. The toxicity of tolnaftate to man on topical application or by an oral administration is virtually negligible (13). Subtotal body inunction (application to 90% of the body surfaces) of 1% w/v tolnaftate solution for 7 days did not show any acute systemic toxicity (16). 

---