The intensity of the inflammatory response in allergic contact dermatitis is dependent on both the sensitizing ability of the allergen and the concentration of the allergen present. Poison ivy is an example of a strong sensitizer that can create an intense inflammatory response, even in small concentrations.[8]

Obtain a thorough history of occupation, hobbies,  medications, lifestyle, use of fragrances, and perfumes. 

Allergic contact dermatitis can present on physical exam as acute or chronic. Acute ACD characteristically presents as an erythematous, eczematous, or vesicular dermatitis. Although ACD may present with a localized, well-demarcated skin eruption most commonly on the hands or face, it can also be more widespread. For example, rinse-off products such as shampoo or body wash may come into contact with many parts of the body, leading to a more diffuse presentation.[9] Additionally, in cases where the patient systemically consumes an allergen, a more diffuse cutaneous reaction may occur. Chronic ACD more commonly presents with lichenification, fissuring, and scale.[10] 

A good clinical evaluation of allergic contact dermatitis involves a detailed history and physical. The morphology and location of the dermatitis is often the best indicator of the offending agent. Patch testing is the gold standard to confirm the diagnosis and should be performed when ACD is suspected in patients with persistent symptoms. Patch testing can help determine the allergen to avoid future exposure. While patch testing is easy to perform, the test may be over-utilized, leading to higher costs for the patient. If the diagnosis is still not certain, a skin biopsy usually demonstrates spongiosis.[11]

One should always rule out tinea as a cause of dermatitis.

The only definitive treatment of ACD is the identification and removal of the offending agent, and all patients with suspected or confirmed ACD should be advised of this. First-line medical therapy includes topical steroids when ACD is confined to less than 20% of the body, and oral corticosteroids when greater than 20% of the body is involved.  If ACD involves a delicate area such as skin folds or eyelids, topical calcineurin inhibitors or PDE4 inhibitors may also be effective. Upon identification of the allergen, strict avoidance is necessary to prevent a recurrence.[12] Symptomatic management includes oral antihistamines, topical hydrocortisone, and cool water soaks. Vesicles should not be ruptured as there is a risk of infection. The use of moisturizers is a recommended adjunct.

For severe cases, topical immunomodulators like tacrolimus may be beneficial. Some patients may benefit from phototherapy using UV A plus psoralen. Rarely in severe cases, one may require immunosuppressive agents like mycophenolate.

In cases of chronic or recalcitrant ACD, use patch testing to identifying the causative agent.[13] Successful patch testing requires several components: choice of appropriate chemicals for testing, a positive patch test to relevant allergens, and patient counseling of patch test results. Additionally, the American Contact Dermatitis Society’s Contact Allergen Management Program (CAMP) can be utilized to generate a “safe list” of products that do not contain the patient’s allergens. In the case where allergens are unavoidable, systemic therapy may be necessary.[14]

Morphologically the clinical presentation of allergic contact dermatitis is very similar to irritant contact dermatitis and atopic dermatitis.[15] Other skin conditions that should be ruled out include drug eruptions, scabies, urticarial bullous pemphigoid, urticaria, psoriasis, seborrheic dermatitis, periorificial dermatitis, and rosacea. 

The goal of the treatment of allergic contact dermatitis is to decrease the inflammatory response that is triggered by the type 4 hypersensitivity reaction. Reactions caused by strong sensitizers may require quicker and more aggressive treatment as the intensity of dermatitis will increase. Identifying and removing the allergen is the most effective definitive treatment. Ointment-based moisturizers and steroids are preferred vehicles of treatment as creams contain a variety of chemicals and preservatives.[16]

The most important step in the management of allergic contact dermatitis is the removal of the offending agent. Toxicities and adverse effects to monitor are related to the treatment options. It is crucial to control the strength of the topical steroids to appropriate dosages as the most common adverse effect of these medications is thinning of the skin.[16]

This disease stays with the affected populations throughout their lives. Strict avoidance of the allergen needs to be the implemented strategy. Management of the inflammatory response is the essential goal in treatment.[12]

The longer a person has ACD, the more time it will take to resolve.

Complications associated with allergic contact dermatitis (ACD) involve the inflammatory response.[4] The inflammation subsides with the removal of the allergen. If the allergen is consumed systemically, diffuse dermatitis might occur, but this condition is not considered a dermatologic emergency.

Unknown causes of allergic contact dermatitis (ACD) may require patch testing, which is best performed by a dermatologist, immunologist, allergist, or physician with clinical experience in analyzing and testing allergic contact dermatitis.

Educating patients on allergic contact dermatitis (ACD) involves assisting the patient in identifying their allergic triggers. Patients must then be provided with practical behavioral modifications to help decrease the inflammatory response of this disease. For instance, in professions that require regular use of rubber gloves, it is essential that patients can identify the natural rubber allergy and choose a glove type that uses a rubber accelerator (i.e., thiurams, carbamates, mercapto compounds) towards which they do not form a reaction.[4]

A diet low in nickel and other minerals has been said to improve symptoms in some patients.

Cross-sensitization may occur in the population affected by allergic contact dermatitis (ACD). This process occurs when an antigen that is chemically similar to an antigen that had previously been sensitized by the host triggers a contact dermatitis. Additionally, systemically-induced allergic dermatitis may take place when an individual who already has undergone sensitization to a contact allergen consumes the allergen by another route (inhalation, ingestion, injection).[17]

The pharmacist is in the prime position to educate the patient on prevention. Patients should be told to avoid wearing nickel-containing jewelry, use latex-free gloves, avoid hair dyes and fragrances which trigger dermatitis. Patients should receive education about reading labels on products to ensure that they do not contain the trigger chemicals. Nurses are also in a strong position to provide counsel on these avoidance strategies.

For those who have ACD of the hands, the use of latex-free gloves may help. Also, patients should use mild cleansing agents on the skin and use protective agents like emollients to help minimize symptoms.

Enhancing patient outcomes is the interprofessional healthcare team's number one priority. Physicians will prescribe treatment when necessary and would do well to verify agent selection and strength with the pharmacist. Nurses should monitor for compliance and also spot adverse events from treatments like topical steroids. Patients with allergic contact dermatitis must have strict return precautions and information on the natural progression of the disease. Patients should not simply receive treatment and sent out the door with a prescription. It is crucial to tailor the treatment to the patient, and the body part affected. Patients also need to have a follow-up with a specialist and continued education. It is vital to utilize nurses and ancillary staff to help communicate in a way that the patient understands. Patients should also have continuous monitoring and follow up with their primary care physician who can help coordinate care. In this collaborative environment, the entire interprofessional healthcare team can direct therapy to its optimal result. [Level V]