Allergic Contact Dermatitis
Understanding, identifying, and treating allergic skin reactions
What is Allergic Contact Dermatitis?
Allergic contact dermatitis (ACD) is a type of eczema that occurs when your skin comes into contact with a substance that triggers an allergic reaction. Unlike irritant dermatitis—which happens when a harsh substance directly damages the skin—ACD involves the immune system. After exposure, your body recognizes the substance (called an allergen) as foreign and mounts an inflammatory response, leading to redness, itching, and often blistering.
Common allergens include:
- Poison ivy, oak, or sumac (urushiol oil)
- Nickel (found in jewelry, belts, eyeglass frames)
- Fragrances and preservatives in personal care products
- Hair dye (paraphenylenediamine)
- Rubber or latex compounds
- Adhesives, topical antibiotics, or other medications applied to the skin
Symptoms
Symptoms usually appear 12–48 hours after exposure to the allergen and may include:
- Intense itching or burning
- Redness and swelling
- Tiny fluid-filled blisters or oozing lesions
- Crusting or scaling as the rash heals
- A sharp border or shape that matches where the allergen contacted the skin
If exposure continues, the rash can become chronic and thickened (a process called lichenification).
Diagnosis
At SOMA Skin & Laser, our dermatologists take a careful history and physical examination to identify likely triggers. In many cases, patch testing is performed to confirm the specific allergen. Small amounts of potential allergens are applied to the skin under adhesive patches, and the skin is evaluated after 48–96 hours for reactions. Identifying the culprit allows for long-term management and prevention.
Treatment Options
The first step in treatment is avoiding the allergen. Once the trigger is identified, your dermatologist will guide you in eliminating it from your daily environment.
To relieve active inflammation, treatment may include:
- Topical corticosteroids to reduce redness and itching
- Topical calcineurin inhibitors (such as tacrolimus or pimecrolimus) for sensitive areas like the face or eyelids
- Antihistamines to reduce itching
- Wet dressings or Burow’s solution (aluminum acetate) to calm oozing or weeping rashes
- Short courses of oral corticosteroids for severe or widespread reactions
For patients with chronic or recurrent ACD, we may also discuss advanced options such as phototherapy or patch-test–guided allergen avoidance plans.
Home Care Tips
- Wash the affected area gently with mild soap and cool water.
- Apply prescribed creams exactly as directed.
- Avoid scratching, which can worsen irritation or cause infection.
- Use fragrance-free, hypoallergenic moisturizers to repair the skin barrier.
- Wear gloves or protective clothing when contact with potential allergens is unavoidable.
When to See a Dermatologist
Seek care if your rash is widespread, blistering, or not improving after several days of home treatment. Persistent or recurring dermatitis often means an allergen is still present or has not yet been identified.
Our experienced dermatologists at SOMA Skin & Laser can help pinpoint the cause, provide effective treatment, and prevent future flare-ups.
If you suspect allergic contact dermatitis, schedule an appointment with SOMA Skin & Laser to receive expert diagnosis and care.