Contact Dermatitis (CD) is a prevalent skin condition that affects 15-20% of the population. Two main types of Contact Dermatitis, a type of skin inflammation due to exposure to an external substance, are Irritant Contact Dermatitis (ICD) and Allergic Contact Dermatitis (ACD). This condition causes itchy, red, and sometimes painful rashes.
Irritant Contact Dermatitis, the most common, occurs when a substance damages the outer skin layer quicker than the skin can repair the damage. On the other hand, Allergic contact dermatitis is an immune system-mediated response. The key difference between ‘irritant vs. allergic contact dermatitis’ is its causes, mechanisms, and management. Keep reading to learn more about them in detail.
Comparative overview of Irritant vs. Allergic Contact Dermatitis
The table below discusses the key differences between Irritant and Allergic Contact Dermatitis, such as the factors behind them, their symptoms, locations, etc.:
| Aspects | Irritants Contact Dermatitis | Allergic Contact Dermatitis |
| The condition | Nonspecific response to direct chemical skin damage and release of inflammatory mediators | Type 4 delayed hypersensitive reaction to allergens, which includes the immune response |
| The reason that causes it | The skin barrier is damaged, causing inflammation | Exposure to allergens leads to rash |
| Prevalence | Nearly 80% of all CD cases | Around 20% of all CD cases |
| Onset of lesions | A few minutes to hours | After 24-48 hours |
| Appearance | Sore or blistering rash | Very dry, scaly, and itchy rash |
| Location | The lesions can appear anywhere but mostly on hands or legs | The rash can be widespread and affect other areas of the body |
| Spreading | Usually restricted to the site of contact with the irritant | The rash may be widespread and affect many regions of the skin |
| Cancerous or noncancerous | Noncancerous | Chronic ACD can lead to Skin Cancer |
| Common signs and symptoms | Typical burning and stinging sores on the skin. Sometimes, blisters (sore filled with fluid) may be seen | The symptoms are similar to Eczema, such as scaly, dry, and itchy skin |
| Causes | Irritants, such as chemicals | Allergens, such as plants, medications, metals |
| Complications | Infection | Infection, Skin Cancer |
| Improvement | Improves rapidly with treatments like Flucort 0.025% | Improves more slowly than ICD |
| Recurrence | Slow recurrence rate | Faster recurrence rate when allergen exposure is re-established |
Allergic vs. Irritant Contact Dermatitis symptoms
The symptoms of ICD and ACD can resemble or vary depending on the severity of the condition or on individualistic characteristics. Some common symptoms of these conditions include:
- Swelling
- Painful rashes
- Itchiness
- Blisters that ooze fluid or pus
- A burning sensation
- Redness
However, some characteristic symptoms that distinguish irritants from allergic contact dermatitis can be seen only in ACD but are somehow absent in individuals with ICD. Some distinguishing symptoms are:
- Dry skin
- Hives
- Hyperpigmented patches
- Skin stiffness
- Discoloration
- Dark skin turning purple, grey, or brown
- Sensitivity to sun
- Ulceration
- Light-complexioned skin turning red
Causes of Irritant vs Allergic Contact Dermatitis
Irritant Contact Dermatitis is caused by repeated exposure of the skin to certain substances that irritate. It can be caused due to both external and internal factors. Some of the most common causes of ICD are:
- Some skin irritants, including oils, soaps, detergents, and solvents
- Mechanical factors, including blockage of blood vessels, pressure, vibration, and friction
- Environmental factors, including heat, humidity, sweating, and cold
- Age, as skin becomes less sensitive to irritants with age
- Sex of an individual, as women are more vulnerable to ICD
Meanwhile, the most common causes of ACD include the following:
- Metals such as Nickel, Chromium, Cobalt
- Balsam of Peru
- Thiomercel, Formaldehyde
- Rubber products, such as latex
- Plants, such as Poison Ivy, Poison Oak, Parthenium
- Skin care products like cosmetics, and fragrance
- Medications, including Antibiotics
- Chemical products
- Tattoo ink
People who are regularly exposed to irritants are at a higher risk of developing Irritant Contact Dermatitis. These include professionals like painters, food handlers, hairdressers, cleaners, and so on.
Additionally, women have a higher probability of developing ACD than men due to being regularly exposed and developing allergies to chemicals, such as Nickel, in cosmetic products.
Treatment of Irritant and Allergic Contact Dermatitis
The treatment for both types of CD is the same, including Contact Dermatitis medications and topical creams like Flucort 0.025% (20 gm) and self-care tips.
The best treatment methods to manage the rash and treat ICD and ACD include oral medications, such as systemic Corticosteroids, oral Antihistamines, and Antibiotics. Topical Steroids, Antibiotics, and Immunomodulators are also often prescribed to control the rash.
Further, some self-care methods are also recommended to prevent severe consequences. For example:
- Identifying the irritants or allergens and trying to avoid them and products that contain them
- In individuals with oozing rashes, using Calamine, oatmeal baths, and Burrow’s solution (Aluminium Triacetate)
- Always using cream or moisturizer after washing
- Using anti-itch creams to relieve itchiness
- Protecting your hands and legs
- Applying cool compresses for 15-30 minutes
- Washing new clothes before wearing them. It will remove the chemical dyes and residues that can trigger an allergic reaction
Conclusion
Irritant vs. Allergic Contact Dermatitis are two main types of Contact Dermatitis. However, there are many similarities between the two types of CD. The symptoms and causes of both conditions can vary; for example, ICD is caused by repeated exposure to irritants, while certain allergens cause ACD. ICD can cause a blistering rash, while ACD can lead to dry, scaly, and itchy rash symptoms.
People working in certain occupations are at a higher risk of contracting the irritant or allergen and developing the conditions. Fortunately, the conditions are treatable, and various medicines, creams, and self-care tips can be utilized to manage them effectively. Furthermore, if the condition persists for longer, it is recommended to consult a healthcare practitioner and seek prompt medical treatment.
