Arizona Sun

Heat and Sunlight Allergy in Arizona: Yes, It’s a Thing

Can you be allergic to heat and sunlight, two things that Arizona has in extreme abundance?  Unfortunately, the answer is yes.

Allergy to Heat

Normally, people do not break out in itchy hives when spending time in the sun or when exercising although people with chronic inducible urticaria (CIndU) might.  In CIndU, hives and sometimes swelling occurs with exposure to a specific physical stimulus such as heat, cold, scratching, sunlight and even water.

CIndU caused by heat is also called cholinergic urticaria. People with cholinergic urticaria frequently have itching, redness, and small hives whenever there is an elevation in body temperature such as might occur with exercise, taking a hot bath, or sitting in a sauna. The rash can also be triggered by emotional stress or eating spicy and hot food. The trunk, arms, and legs are most frequently involved and the rash usually lasts from 15 minutes to an hour.

The diagnosis is usually apparent from the history but can be confirmed by an exercise challenge.

Treatment usually begins with non-sedating antihistamines such as Claritin, Allegra, Zyrtec or Xyzal.  Antihistamines alone are frequently beneficial although it may take up to four times the usual dose to get things under control. More resistant cases have been treated with a variety of other medications including Xolair given by injection once a month.

Exercise-induced Anaphylaxis

Exercise-induced anaphylaxis is a more serious form of heat allergy. In this condition patients not only break out in hives but can have difficulty breathing and even lose consciousness from a drop in blood pressure with exercise. In some cases, the severe reaction to exercise only occurs if certain foods, such as wheat or peanut, are eaten before the activity.   A careful exercise challenge can confirm the diagnosis and allergy testing can pinpoint the food allergy component.    All patients with this condition should carry an EpiPen, never exercise alone, and strictly avoid food triggers before exercise.

Allergy to Sunlight

It sounds odd and certainly unfortunate if you live in Arizona, but some people will breakout with hives whenever their skin is in direct contact with sunlight for more than a few minutes. This condition is called solar urticaria.

The hives appear on sun-exposed skin several minutes after exposure to a specific wavelength of light and usually last for less than a day as long as you get out of the sun. Covering up to avoid direct contact with the sun is usually helpful although sunscreen, because it does not block the wavelengths of light causing the problem, is not. Phototesting can not only confirm the diagnosis
of solar urticaria but can identify the specific wavelengths of light causing the problem.

Sensitivity to sunlight can cause several other skin disorders called photodermatitis. These conditions, like solar urticaria, occur on sun exposed skin but typically last longer than 24 hrs.

The only thing worse than being allergic to sunlight and heat while living in Arizona is being allergic to dust –  that is definitely a thing.

New Treatment for Chronic Hives On The Way

Hives are never fun.  Intolerable itching, grotesque swelling, nasty red splotches and welts covering the body, hives can clearly make for a very bad day.   The only thing worse than a brief (acute) attack of hives is an unrelenting, daily outbreak lasting for months and even years.  Such is the case with patients with chronic hives.

Chronic hives not only linger for what must seem like an eternity, but in 95% of cases, no cause for the misery is found.   When a condition or disease occurs without a known cause, it is referred to as idiopathic.  The term we use for hives that last longer than several months and do not have an identifiable cause is called chronic idiopathic urticaria or CIU.

For some patients, a daily antihistamine is all that is needed to control outbreaks. They are the lucky ones.   For others, large doses of antihistamines, up to four a day, as well as high doses of steroids are required.  When this fails, other medications, some used in the treatment of organ transplant rejection, most with serious side effects, are needed just to stay clear.

Any news of new treatment options for CIU are welcome.  This news may be coming in the form of a new indication for a not-so-new asthma drug.  In Europe, Novartis’ asthma drug Xolair (omalizumab) was approved for the treatment of (CIU).  It is expected that approval in the US will follow soon.

The good news is that it will provide a much needed alternative for patients whose symptoms cannot be controlled with antihistamines alone, and need daily steroids.

The bad news is that Xolair is a genetically engineered wonder drug. Specifically it is a glycosylated IgG monoclonal antibody produced by cells of an adapted Chinese hamster ovary cell line and secreted in a cell culture process employing large-scale bioreactors.  All of this means it is very, very expensive; about a thousand dollars per injection (it is given by injection by the way) and two shots a month are often needed.  Since CIU is a chronic condition without a cure, the injections may be needed for many, many years.

This “good news” is coming at a time when high deductible insurance plans are becoming the norm so most of the cost of medications, including the thousand-dollars-an-injection variety,  will be out of pocket for the patient.    I am not sure how much more “good news” some patients will be able to stand.

What Are Hives?

Hives is the common term for urticaria, a unique type of skin rash characterized by itchy, raised, welts, which may be few and isolated or large and numerous, covering large areas of the body.   Welts frequently form at sites of scratching or pressure such as around the waist or bra strap. Individual welts last only a few hours and then fade, only to be replaced by new lesions.   Other itchy rashes are frequently mistaken for hives.   If individual bumps last more than 24 hours then the rash is not typical hives.

We know what causes hives but we do not always know why.   Hives are the result of chemicals such as histamine released from a white blood cell in the skin cell called the mast cell.  Everyone has histamine-filled mast cells in the skin but as long as the histamine stays in the cell, it does not cause problems.  When the histamine is released, which occurs commonly in an allergic reaction, the result is redness, itching and swelling.   An allergic reaction to pollen typically causes itching, swelling and dripping of the nose as histamine is released in the nasal tissue from mast cells coming into contact with the pollen.   A reaction in the airways may cause an asthma attack.  In food allergy, the allergen, usually a protein, is absorbed into the blood stream and is distributed around the body.  Mast cells in the skin react to the food protein and release histamine.  Histamine released in the upper layers of skin cause hives while histamine released in the deeper layers may cause itching and swelling without obvious rash, a condition called angioedema.    A severe allergic reaction will cause sudden, widespread release of histamine .  Such a dramatic  release of histamine into the tissues of the body may result in a rapid drop in blood pressure as well swelling of the tissues around the throat and airways compromising breathing.  This rare but serious allergic reaction is called anaphylaxis.

Allergy is common and most true allergic reactions involve release of histamine from mast cells and, while allergic reactions to foods, insect stings, medications, contactants, and on occasion airborne allergen, frequently cause brief outbreaks of urticarial rash, hives that last more than 4-6 weeks are rarely caused by simple allergy.    In fact, in more than 90% of cases of hives lasting more than 6 weeks, an allergic cause for the rash cannot be found.   In these cases, the diagnosis is Chronic Idiopathic Urticaria.

Because the rash, itching an swelling of hives is for the most part caused by histamine, antihistamines are the primary treatment. Corticosteroids are often used for a short time get a bad case of hives under control although the side effects associated with long term use of oral steroids makes there daily use unworkable.   The dose of antihistamines required to treat chronic urticaria can be more the four times the dose commonly used to treat nasal allergies.

Hives are uncomfortable, at times scary, and almost always frustrating.  The desperate search to understand and eliminate the cause for the horrible rash and itching is usually unfruitful.  However, with proper treatment, it is manageable and usually (but not always) resolves in time.

Allergic Skin Conditions (overview)

There are several types of allergic skin conditions. They are often itchy and red and may appear scaly, bumpy or swollen. An allergist can determine which condition you have and develop a treatment plan to help you feel better.

While skin allergies are unpleasant and troublesome, there are things you can do to treat them.

Hives and Angioedema
Hives (or urticaria) are red, itchy, raised areas of the skin that can range in size and appear anywhere on your body. Most common are acute cases, where food or drug allergies are triggers. These hives usually go away within a few days. In cases of chronic hives (lasting more than six weeks), people may suffer for months to years.

Angioedema is a swelling of the deeper layers of the skin that sometimes occurs with hives. The areas often involved are the eyelids, lips, tongue, hands and feet.

Food or drug reactions are a common cause of acute hives and/or angioedema. Viral or bacterial infection can also trigger hives in both adults and children. Physical urticaria are hives resulting from a non-allergic source: rubbing of the skin, cold, heat, physical exertion or exercise, pressure and direct exposure to sunlight.

If the cause of your hives can be identified, you should avoid that trigger. With acute hives, some drugs or foods may take days to leave the body, so your allergist may prescribe antihistamines to relieve your symptoms until that happens.

Contact Dermatitis
When certain substances come into contact with your skin, they may cause an eczema-like rash. There are two types of contact dermatitis: allergic and irritant. Irritant contact dermatitis is caused by substances that cause burning, itching or redness in all people if the exposure dose or duration is long enough. It is a common problem in people who wash there hands too frequently. An example of allergic contact dermatitis is the itchy, red, blistered reaction experienced by some people after contact with poison ivy. This allergic reaction is caused by a chemical in the plant called urushiol. Only some people will react with this chemical and is some cases, the reaction is severe. You can have a reaction from touching other items the plant has come into contact with. Allergic contact dermatitis reactions can happen 24 to 48 hours after contact. Once a reaction starts, it takes 14 to 28 days to go away, even with treatment.

Other common cause of allergic contact dermatitis include nckel, perfumes, dyes, rubber (latex) products and cosmetics also frequently. Some ingredients in medications applied to the skin can cause a reaction, most commonly neomycin, an ingredient in antibiotic creams. For irritant contact dermatitis, you should avoid the substance causing the reaction. Gloves can sometimes be helpful. Since these reactions are non-allergic, avoiding the substance will relieve your symptoms and prevent lasting damage to your skin.

Treatment for allergic contact dermatitis depends on identifing and avoiding the offending agent. If the allergen can not be readilly determined by history, allergy patch tests may be used to help identify it. To relieve symptoms, you may be prescribed topical a corticosteroid cream and in severer cases, an oral corticosteroid for a few days may be required.

Atopic Dermatitis
A common allergic reaction often affecting the face, elbows and knees is atopic dermatitis or eczema. This red, scaly, itchy rash is more common in young infants and those who have a personal or family history of allergy.

Common triggers include aeroallergens like cat dander or house dust, overheating or sweating, and contact with irritants like wool or soaps. In older individuals, emotional stress can cause a flare-up. For some patients, usually children, certain foods can also trigger eczema. Skin staph infections can cause a flare-up in children as well. Eczema patients usually have very dry skin and “allergic shiners” (an extra crease, called a Dennie’s line, across their lower eyelids). They are also more at risk for other skin infections.

Preventing the eczema itch is the main goal of treatment. Do not scratch or rub your rash. Applying cold compresses and creams or ointments is helpful. Also remove all irritants that aggravate your condition from your environment. If a food is identified as the cause, it must be eliminated from your diet.

Topical corticosteroid cream medications and topical calcineurin inhibitors are most effective in treating the rash. Antihistamines are often recommended to help relieve the itchiness. In severe cases, oral corticosteroids are also prescribed. If a skin staph infection is suspected to be a trigger for your eczema flare-up, antibiotics are often recommended.


What is Eczema?

Eczema is a general term for any type of dermatitis or “itchy rash”. There are several skin diseases that are eczemas; a partial list of eczemas includes:

* atopic dermatitis
* contact dermatitis
* dyshidrotic eczema
* nummular eczema
* seborrheic dermatitis

All types of eczemas cause itching and redness and some will blister, weep or peel.

Atopic Dermatitis (AD)
Atopic dermatitis is the most severe and chronic (long-lasting) kind of eczema. Atopic dermatitis is a disease that causes itchy, inflamed skin. It almost always begins in childhood, usually during infancy. Physicians estimate that 65 percent of eczema patients are diagnosed in the first year of life and 90 percent of patients experience it before age five. Often the symptoms fade during childhood, though “most” will have AD for life. It is estimated that atopic dermatitis affects over 30 million Americans. It typically affects the insides of the elbows, backs of the knees, and the face but can cover most of the body. Atopic dermatitis falls into a category of diseases called atopy, a term originally used to describe other allergic conditions such as asthma and hay fever. Physicians often refer to these three diseases as the “atopy triad” and AD may be first to appear in what has been called the “allergic march”, the progressive manifestation of allergic conditions from infancy to adult. Although many patients with atopic dermatitis will test postive to several foods on allergy tests, less than 30% of patients with AD will improve when those food are elliminatted. It is safe to say, therefore, that atopic dermatitis is directly related to the conditon of allergy but not necessarily to any one allergic trigger.

Contact Dermatitis (Allergic or Irritant)
Contact dermatitis is a reaction that can occur when the skin comes in contact with certain substances which can cause skin inflammation. Irritants are substances that cause burning, itching or redness in all people if the exposure dose or duration is long enough. Common irritants include solvents, industrial chemicals, detergents, fumes, tobacco smoke, paints, bleach, woolen fabrics, acidic foods, astringents and other alcohol (excluding cetyl alcohol) containing skin care products, and some soaps and fragrances. Allergens are specific substaces, typcially proteins from foods, mold, pollen, or pets, that only sensitized individuals will react to. Contact dermatitis is considered a type of delayed hypersensitivity reaction because it may take 24-48 hrs after contact before the eczmea developes.

Dyshidrotic Dermatitis (Pompholyx)

This is a blistering type of eczema, which is twice as common in women. It is limited to the fingers, palms, and soles of the feet. The hands may have small,tense, fluid filled blisters, scaly patches of skin that flake constantly or become red cracked and painful. Itching is usually severe.

Seborrheic Dermatitis

Red, scaly, itchy rash in various locations on the body. The scalp, sides of the nose, eyebrows, eyelids, and the skin behind the ears and middle of the chest are the most common areas affected. Dandruff (as seborrheic, is caused by a fungal infection) appears as scaling on the scalp without redness. Seborrhea is oiliness of the skin, especially of the scalp and face, without redness or scaling. Seborrheic Dermatitis has both redness and scaling.

Treatment of Eczema

Prescription drugs vs over the counter medications?

Over-the-counter (OTC) medications are available without a prescription because they contain the lowest potency of active ingredients. They are not designed to treat the causes of a disease, but to give some relief of symptoms. Many good moisturizers are available as OTC products. They are important in terms of prevention and maintenance to reduce eczema’s impact. Regular use of these products may reduce the frequency of flare-ups. Prescription medicines, by contrast, are usually much more powerful in providing some relief of the symptoms. They are closely regulated in the U.S. by the Food and Drug Administration (FDA), and are approved for use in treating a specific disease only after they have demonstrated effectiveness and safety. No prescription drug is free of side effects, and FDA approval is given to drugs with the understanding that they must be used with caution to avoid the negative effects which could result in something worse than the disease itself. Consequently, these drugs must be administered under the watchful eye of a licensed prescriber-a doctor, or in some states, a nurse practitioner.

What are FDA approved prescription therapies?

Topical steroids have been the standard treatment for eczema, with oral steroids being prescribed only for severe flare-ups. Recently, however, the FDA has approved a new class of drugs called Topical Immunomodulators (TIMs). At this time there are two FDA approved non-steroid drugs: tacrolimus and pimecrolimus. Topical anesthetics, antibiotics, antihistamines, antibacterial, antifungal and anti-inflammatory drugs are available in creams, gels, ointments, lotions and solutions. Most of these classes of drugs can also be administered orally.

What about alternative or complimentary medication?

Alternative medications also have ingredients that may have irritating or allergenic effects for some people, as with any treatments. It is important to discuss with your physician any alternative medication that you may purchase at a health food store as it may have an adverse reaction to your eczema or another medication you may be taking.

Are there plants and vegetables to avoid?

Everyone knows about obvious culprits like poison ivy, poison oak and stinging nettles, but for people with eczema trying to avoid any plants with fuzzy leaves and stems is a good idea.
Alliums, which include garlic, onions, chives, and leeks, tend to contain allergens that are more irritant than allergen. Citric fruits like lemons, limes and oranges may cause phototoxicity problems. You can get a severe rash from contact with a mango rind. The saps of certain trees are also phototoxic. Daisies (member of a family which includes dandelions, artichokes, chrysanthemum, sunflowers and yarrow) contain a variety of the allergens called sesquiterpene lactones in their stems, leaves, and flowers. If handled, they can produce a localized rash, and they (particularly dried ragweed) may also cause airborne contact dermatitis. Tulips contain an allergen called tuliposideA that often causes a fissured, fingertip dermatitis called “tulip fingers”. Poinsettias are also very irritating mostly because of a sticky sap it exudes. Handle all plants diligently (or with latex free gloves).