Contact dermatitis

In this article:

• How do dermatologists diagnose contact dermatitis?
• Treatment for contactdermatitis
• Over-the-Counter (OTC) Therapies
• Prescriptions
• Specialist-Driven Procedures
• Home Remedies and Lifestyle

How do dermatologists diagnose contact dermatitis?

Contact dermatitis appears as a rash often described as red and itchy, typically with bumps and sometimes blisters. This rash often closely resembles eczema and other forms of dermatitis which requires careful investigation to ensure the correct diagnosis is made. Dermatologists diagnose contact dermatitis by asking specific questions to understand the context, pattern, timeline, location, and environmental factors surrounding the development of the rash. Contact dermatitis is characterized by exposure to a chemical or substance that irritates or elicits an allergic response in the skin — discovery of this substance is the key to making the diagnosis and treatment plan. Habits, daily routines, laundry detergents, sanitary products, workplace exposures, skin soaps, and facial cleansers should all be considered. The most commonly involved areas are the hands. The face is often involved if the offensive substance is aerosolized or related to cosmetics1. While testing is not usually necessary to diagnose contact dermatitis, if an allergic cause is suspected, allergy skin patch testing may be used to help determine the cause. In some cases skin biopsy may also be utilized. 

Treatment for contactdermatitis

The treatment of contact dermatitis is centered on the identification and avoidance of the causative substance. The most simple and effective method for improving contact dermatitis is to reduce and eliminate exposure. If the offending substance is clear, for example a new makeup or chemical handled at work, making lifestyle changes to avoid contact is an easy solution. In situations where exposure is unknown, using forms of personal protection may be helpful. 

For example, wearing long pants that cover your legs while hiking, or wearing gloves that extend past your elbows while handing chemicals at work. In addition to preventative measures, active treatment methods include topical medication such as steroid creams to reduce inflammation, as well as restoration of the skin barrier with moisturizing lotions and creams.

Over-the-Counter (OTC) Therapies

For all forms and severities of contact dermatitis, skin barrier protection and miniaturization are important for recovery. Topical creams and lotions containing occlusive emollients (e.g. lanolin, mineral oil, ceramides) and humectants (e.g. glycerin, propylene glycol) help the skin to absorb and retain moisture. 

Scented lotions or creams are not recommended as they have the potential to cause allergic reaction. Most forms of contact dermatitis are prescribed a high potency topical steroids to improve itching and redness associated with the rash. Over the counter formulations of topical steroids are less potent but may be able to provide some symptomatic relief. 

Prescriptions

Topical corticosteroids paired with moisturizing lotions and creams are a common treatment for contact dermatitis. For mild to moderate cases of contact dermatitis on the body, a high potency topical steroid is often prescribed for use in combination with moisturizing barrier creams. Special considerations are given for contact dermatitis on the face and folds on the body (aka flexural surfaces) where a lower potency steroid cream is often preferred. 

Specialist-Driven Procedures

While most cases of contact dermatitis can be diagnosed through careful questioning, there are cases where further testing is warranted. For situations where an allergic cause of contact dermatitis is suspected but is difficult to identify, an allergy specialist may be asked to perform an allergen patch test. During this test, a small sample of several potential allergens are introduced to the skin on patches. After a few days, the skin is examined for reaction and if present. Correlated to the substance on the patch. 

Not routinely ordered for the evaluation of contact dermatitis, a skin biopsy may be useful to exclude other possible diagnoses.

Home Remedies and Lifestyle

The majority of the treatment for contact dermatitis is lifestyle. After identifying the irritating substance, modifying your lifestyle to avoid or limit contact with the substance is the most effective way to prevent contact dermatitis from recurring. When complete avoidance of the substance is not possible, personal protective equipment must be used to minimize contact and exposure. Sanitary gloves can be worn to prevent contact dermatitis on the hands. Masks, face shields, or hairnets may be used to limit exposure to the face. 

Many forms of barrier cream can be made with household products. Neutral oils such as olive oil, vegetable oil, or coconut oil can be combined with Aloe Vera gel and shea butter to form an effective moisturizing and protecting cream. Zinc oxide may also optionally be added to provide sun protection.

The Soak and Seal method is a technique for treating and retaining skin moisture for patients with forms of dermatitis and can be combined with homemade barrier creams and OTC products. The Soak and Seal can be performed by following these steps:

• Fill bath with warm water and soak for 5 – 10 mins
• Pat dry the skin leaving it damp
• Apply topical medications to the rash as directed
• Within 3 minutes apply moisturizing product liberally all over the body
• Wait for the moisturizer to absorb into the skin before dressing

1. Rietschel RL. Clues to an accurate diagnosis of contact dermatitis. Dermatol Ther 2004; 17:224.
2. Held E, Lund H, Agner T. Effect of different moisturizers on SLS-irritated human skin. Contact Dermatitis 2001; 44:229.
3. Clemmensen A, Andersen F, Petersen TK, et al. Applicability of an exaggerated forearm wash test for efficacy testing of two corticosteroids, tacrolimus and glycerol, in topical formulations against skin irritation induced by two different irritants. Skin Res Technol 2011; 17:56.
4. https://nationaleczema.org/wp-content/uploads/2018/03/FactSheet_SoakSeal_FINAL.pdf