Urticaria and angioedema
Urticaria or hives are swollen, pale red bumps, patches, or welts on the skin. Hives usually cause itching and can affect any part of the skin. Urticarial hives is usually due to allergy.
Angioedema is similar to hives, but the swelling occurs beneath the skin instead of on the surface. Angioedema is characterized by deep swelling around the eyes and lips and sometimes of the genitals, hands, and feet. These swellings commonly last for more than 24hrs, and usually there is no itching. Some drugs like Beta blockers, ACE inhibitors, aspirin, NSAID etc can cause angioedema, and there is also a rare inherited form called hereditory angioedema.
Chronic urticaria and/or angioedema: Hives or swelling lasting more than six weeks.Besides allergy the causes can be autoimmunity, chronic infections, hormonal disorders, and malignancy.
Physical urticaria: Hives caused by direct physical stimulation of the skin — for example, cold urticaria, heat urticaria, sun exposure (solar urticaria), vibration, pressure, sweating, and exercise induced urticaria.
Dermatographism: Hives that happen after firmly stroking or scratching the skin.
Hereditary angioedema: It is passed on through families. It is due to defect in C1 esterace inhibitor.
Atopic eczema (also called atopic dermatitis) is inflammation of the skin with intense itching, reddening, dryness, blistering and scaling. Since not all cases are linked to allergy, the preferred term is “the Atopic Eczema/Dermatitis Syndrome” (AEDS). Atopic dermatitis is not contagious – it cannot be transmitted by, or to, another person. Atopic dermatititis is usually associated with high IgE antibody in blood. More common in children.
Allergy to cosmetics
Reaction to cosmetics can be an irritant effect, or contact dermatitis. Allergic contact dermatitis is an example of a delayed-type allergy and the reaction may not appear until several hours or even days after using the product. Allergy patch testing helps to diagnose contact allergy to cosmetics.
Reaction to cosmetics can be an allergic response or irritation.
Allergy to hair dye
Hair dye can cause irritant contact dermatitis or more commonly cell mediated type four allergic contact dermatitis. But may also produce a systemic reaction affecting whole body. The local irritation will tend to affect the scalp, neck, forehead, ears and eyelids; the generalized symptoms may include more widespread itching, urticaria (nettlerash), general malaise or, rarely, anaphylaxis (allergic shock).
Hair dye allergy is usually due to Paraphenylenediamine (PPD) is found in permanent hair dyes, especially those at the darker / black end of the range.
Because PPD is known to be a strong sensitiser in some people, people try alternatives hair dyes, Para-aminodiphenylamine (PADA) and paratoluene diamine (PTDA) and 3-nitro-p-hydroxyethylaminophenol (usually found in dyes at the less dark, ‘redder’ end of the spectrum) are somewhat less troublesome than PPD, but can still cause sensitivity problems
Nickel allergy typically develops following ear piercing and the use of metal jewelry. The allergy results in the development of a localized eczema/dermatitis.
Pure gold (22 carat or more), solid silver and platinum are usually safe alternatives for jewelry. Other metal objects in prolonged contact with the skin such as watches, buckles, clips in underwear, spectacle frames and mobile phones can also cause contact dermatitis due to nickel allergy.
Sun allergy is called polymorphic light eruption (PLE). This begins with the first strong sun exposure in the spring or a sunny holiday. In many individuals, the problem gets better through the summer as the skin gets used to the higher light levels.
Polymorphic light eruption can be triggered by UVA as well as UVB in sunlight and can develop indoors and if wearing loose weave clothing as UVA can pass through.
To reduce sun exposure one can use close weave clothing, hats and keeping out of the sun. Sunblock creams may help, but it is important to use a high Sun Protection Factor (SPF) cream, at least SPF30, which has both UVA and UVB protection. But high protection sun blocker can itself cause contact allergic dermatitis.
Blue dye allergy
In our allergy and weight loss center, we re seeing increasing number of patients that react to disperse blue clothings, medicines etc. Allergy patch test shows positive reaction to disperse blue.