Allergic Skin Reactions: Contact Dermatitis
- Victoria Wermers, RN,MSN,FNP, PMHNP
- Sep 23, 2024
- 9 min read
Updated: Jul 11
Skin Allergies (Contact Dermatitis) When you are allergic to something, the immune system mistakenly overresponds and senses that substance as a foreign body. The body hyper-responds by flooding the area or system with white blood cells (especially IgE), and histamine. Suddenly, histamine causes swelling, inflammation, and often itching. A skin rash breaks out (among other things).
Common Manifestations of Contact Dermatitis
redness
itching
swelling
scaling
blistering
mouth sores, especially with citrus
Very occasionally, there may be wheezing and other respiratory symptoms
There are lots of things that can cause skin rashes. The biggest perpetrators are certain foods, medications, plants, and chemicals. Periodically, a rash is caused by a virus or bacteria, but you must consider contact dermatitis (skin allergies) when the cause is unknown. Contact dermatitis (immune reaction) and irritant dermatitis (non-immune reaction) occur when the skin comes in contact with a foreign substance. It is often manifested by itching, redness, scaling/flaking, dryness, sometimes little red bumps, sometimes "patchy" areas, occasionally a hive-like rash, or "weepy" blisters. If you have ever had poison ivy, sumac, or oak, you know what it is!!
Common skin reactions occur due to contact with plants (as in the notorious "poison ivy," oak or sumac), cloth, a chemical (soap, detergents, cleaning solvents, polishes, dyes, hand and face soap, shampoos, metals (i.e., jewelry) fertilizers and pesticides, cosmetics, perfumes, PABA - in sunscreen lotions). The rash can come from latex (from disposable gloves, condoms, and balloons); from metals, and even from sunlight! (rare). It is interesting to note that latex-allergic people can also have a cross-sensitivity to kiwi, banana, avocado, chestnut, papaya, fig, potato, and tomato.
Even herbs can cause allergies. This is especially important if someone is interested in using herbal remedies. Some of the most likely herbs to cause contact dermatitis are in the Asteraceae family: Echinacea, daisies, chrysanthemum, chamomile, tansy, dandelion, feverfew, and sunflowers.
What Is Causing My Rash?
Rashes are one of the problems that our patients often Google before coming in. If you are not sure what is causing your rash, consider contact dermatitis. You want to ask yourself a few questions:
Where is the rash? How is it distributed on your body? Does it look as if it was under clothing (is the rash JUST under clothing)? Then, it is likely due to the detergent on the cloth that has been against your skin or even the fabric itself. Is it only on your face? Think makeup or facial cleanser.
Have you changed certain products, or are you using a new product?
Have you been hiking or doing work in the yard? Think of plants like poison ivy or oak, which cause a characteristic itchy rash, often spreading and characterized by blisters that pop and scab. It is often difficult for people to understand how this spreads from one part of the body to a totally different body area. Contrary to what people sometimes believe, it does not get into your blood. It is caused by oils being spread from one area of your body to another.
Is the rash in a place where you have been wearing jewelry?
Sometimes, a plant allergy, such as poison ivy, a food allergy, or a medication allergy, can cause a rash. Sometimes, it is from a bite or sting, a virus, or bacteria. Sometimes, it is atopic dermatitis (eczema) or chemical dermatitis (from contact with a chemical). It can be difficult to tell the difference, but clues often exist.
Occasionally, a person will not know what caused the rash - has never had anything like it before, and cannot connect it with anything familiar. When the cause is not evident through the above questions, and we cannot determine a cause, we typically ask a patient to keep a diary of events for about 24 hours before developing the rash:
Activities prior to rash onset
Foods or drinks consumed
Use of body soaps, shampoos, detergents, cosmetics, and other topical products
Review any new medications taken within the past 1–2 weeks, as these may be contributing factors.
When all else fails, a person can go to an allergist and get bloodwork or a patch test. If it commonly occurs, a person can even order their own bloodwork online to determine allergies.
About Poison Ivy (Plant dermatitis)
Discussion of poison ivy is essential in this article, Allergic Skin Reactions: Contact Dermatitis. We frequently see these rashes at our clinic, caused by poison ivy and, occasionally, poison oak. Some people are extremely sensitive to these plants (while others show no reaction at all). Interestingly, individuals who’ve never experienced a reaction can suddenly develop one later in life. With repeated exposure, even those with prior reactions often find that successive cases may worsen each time.
How it Spreads
Most people with poison ivy know they were exposed or recall being outdoors prior to developing a rash. It begins in one small spot, then spreads and spreads. Some believe that it travels in the bloodstream, but it does not do that. It spreads through contact with oils (elsewhere on your body and clothes, pets, etc. Many people don’t realize they’ve spread poison ivy to other parts of their body, especially while sleeping or absentmindedly scratching. It’s also worth noting that outdoor pets that have been roaming in the weeds can carry the plant’s oils on their fur and unintentionally transfer them to humans. However, it’s extremely rare for poison ivy to spread directly from person to person, as the rash itself isn’t contagious—only the oil is.
How to Treat It
Many skin rashes caused by contact are treated in the same way. Follow the directions below - Approaches to skin rashes. Additionally, there are two major products on the market, Tecnu and Zanfel. These products will help remove the plant toxins from the skin and will hopefully stop irritation. But these must be used soon after exposure to the plants. Otherwise, you will end up spending plenty of money without success.
Prevention is the key. If you are unable to cover exposed surfaces, you can try to use a wash, if there is any suspicion that you have been exposed, wash the entire area very thoroughly with soap and water to remove the plant oils. You can also use rubbing alcohol. Do not scrub hard. Wash clothing and any equipment well. Bathe pets.
One last note: Do not burn poison ivy plants. Never burn poison ivy, poison oak, or poison sumac! If you burn it and breathe it in, it can be extremely toxic to your lungs.
Allergic Skin Reactions: Contact Dermatitis
Approaches to Skin Rashes
General Approaches to Skin Allergies
1. Keep the area clean and dry - wash with gentle soap - there are MANY labeled as "gentle" (avoid harsher fragrance and antibacterial soaps)
Avoid further exposure (of course).
Do not scratch (it might feel good, but it tends to cause the rash to spread).
Avoid hot water on the rash (it sometimes feels "good" but often makes the rash worse).
Generally speaking, occlusive dressings should not be used on poison ivy unless there is a NEED to cover them temporarily (i.e., potentially dirty environments). Air helps these rashes dry.
Warm Epsom salt bath or compress
A cool, moist compress for 15-20 minutes at a time
Over-the-Counter Approaches to Contact Dermatitis
1. Non-fragrance moisturizers may help small, dry and flaky areas. 2. Topical treatment applied to the skin can also be used for smaller areas. You can try an over-the-counter low-dose hydrocortisone (topical steroid , which decreases inflammation, itching, and redness).
3. Calamine, Caladryl (also called pramoxine, an anesthetic that decreases pain).
4. Baking soda paste (1 part baking soda: 3 parts water)
5. Oral antihistamines like Benadryl, Zyrtec, Allegra, or Claritin for itching. Some forms of dermatitis, like poison ivy, may not respond very well to the over-the-counter medication
approaches, in which case you may want to get a more effective prescription from a healthcare provider.
Considered Alternative and Herbal Approaches
While many of these may be helpful, they can also cause skin irritation.
The following are possible remedies for allergic dermatitis and come in various creams, ointments, salves, and other types of applications:
Jewel Weed (may help when applied as a compress on irritated skin)
Chamomile (also tea compress)
Witch Hazel (cream, liquid)- especially helps oozing lesions
Mullein
Oatmeal (has some anti-inflammatory properties)
Prescriptive Treatment of Allergic Approaches to Contact Dermatitis
See a healthcare provider if you have had your rash for a week or more, if it is over a large portion of your body,, or if it is on your face or eyes; if the itching is just driving you nuts or if you have any difficulty breathing
Typical Prescription Treatments
1. Oral steroids: As mentioned above, if the rash is extensive, an oral steroid, prednisone, is given, starting with a high dose and gradually titrating over several days to a low dose. It is imperative that the rash is totally GONE at the end of the course of steroids ; otherwise, it may come back with a vengeance.
2. Topical (applied to skin) steroids are typically used for smaller areas of the skin when your skin is less than 20% affected by the rash (1). There are a number of strengths that range
from low dose, medium/moderate dose, to high dose, and super/ultra high dose.
Typically, if topical steroids are going to be used for contact dermatitis, they include the more commonly prescribed topical medicines such as the following:
Hydrocortisone (low and medium strength)
Triamcinolone (low to high potency)
Betamethasone (medium and high potency)
Clobetasol (super/ultra potency)
Desonide (low potency)
Fluticasone (high potency)
These medications can be used along with or instead of oral corticosteroids.
Note: For severe ongoing cases, unavoidable exposures, and for those in whom other
treatments are contraindicated, phototherapy or immunomodulating medications are very
occasionally used.
Skin Allergies/Rashes: Q&A
I have had a good number of poison ivy and poison oak patients in my clinic, and many times the following questions arise:
Can topical steroids (creams and gels) go through my skin and get into my bloodstream?
Although not as common as oral steroids, topical steroids CAN be absorbed
through the skin and enter your bloodstream. Most topical steroids are prescribed for short-term use: Ultra-high potency steroids are typically prescribed for no longer than three weeks; low to high potency are usually prescribed for no longer than three months (2). This is because they can cause long-term side effects. Potential side effects of topical steroids, especially of prolonged ultra-high topical steroid use -may include the following: Skin thinning, stretch marks, bruising, changes in skin color, and hair growth in the area of application may (rarely) depress the immune system, premature skin aging, "pseudo scars," eye problems (3)
Creams vs ointments - Which is better?
Topical steroids come in several different forms, including lotions, creams, shampoos,
sprays, and foams. Creams and gels are generally used more for "blistery" or vesicular areas, and ointments for dry, scaly areas, usually in more chronic conditions. Ointments are used for scaly, dry-type rashes. Ointments are typically more potent.
Some literature refers to "salves" - these are generally thick and include creams, ointments, and balms (fragrant ointments).
Do NOT apply to the open part of the wound unless directed to do so by a healthcare provider.
A Note About Latex Allergies:
Latex allergies are not as common as they may seem. Many of us have changed the types of gloves we use in dentistry and healthcare (actually, according to the Occupational Safety and Health Administration, 8-12% of healthcare providers have latex allergies); we avoid giving certain vaccinations because of latex packaging. It is, in fact, reported that there are approximately 1,700 people who have reported latex allergies since 1988.
Some of the many items, other than those above, may be elastic in clothing, household items like floor mats, paint, condoms, baby items made of rubber, balloons, and desk supplies like erasers and rubber bands, to name only a few.
If you have a latex allergy, be aware that there are some cross-sensitivities with certain foods. If you are allergic to latex, you may have an allergy to the following foods:
Apple, avocado, banana, celery, chestnuts, carrot, celery, chestnut, kiwi, melons, figs, melon, papaya, tomatoes, strawberries, and raw potato.
Not everyone with latex allergies has all of these food cross-allergies, but it is important to be aware that they could be a problem.
Signs and symptoms of latex allergies include some of the following:
Itching, redness, and swelling of the skin exposed to the latex. Respiratory symptoms like a runny nose, nasal congestion, sneezing, itchy eyes, eye-watering, wheezing, coughing, possibly shortness of breath, and even anaphylaxis, among others.
NEVER FOOL AROUND WITH SEVERE ALLERGIES - ESPECIALLY IF THEY ARE AFFECTING YOUR MOUTH, AIRWAY, OR FACE! SEEK MEDICAL ASSISTANCE RIGHT AWAY!
SERIOUS ALLERGIES? CARRY AN EPI-PEN!!!
