Skin Allergy (Contact Dermatitis)

Contact dermatitis is skin inflammation triggered by direct contact with a substance. This reaction may be caused by an irritant or allergen and appears as redness, itching, dryness or blistering. It is a common condition that can affect anyone – especially those with sensitive skin or frequent exposure to harsh substances.

Unlike infections, this condition is not contagious. However, it can significantly affect quality of life, especially when exposure is ongoing or difficult to avoid in certain occupations.

The condition is considered an allergic reaction when it is triggered by the immune system (allergic contact dermatitis). It can also result from non-allergic irritation, particularly with repeated use of chemicals.

What are the types of Contact Dermatitis?

There are two main types of contact dermatitis, each has different causes:

• Irritant Contact Dermatitis (ICD) – this is the more common type. It is caused by direct chemical damage to the skin from repeated or prolonged exposure to irritants such as detergents, hand sanitisers, bleach or solvents. It typically develops gradually with ongoing exposure and does not involve an allergic response.
• Allergic Contact Dermatitis (ACD) – this is a delayed immune reaction to a perceived allergen. Common allergens include nickel, fragrances, preservatives, rubber, and hair dye ingredients. Once sensitised, even small amounts of exposure can trigger a reaction.

What causes Contact Dermatitis?

The condition occurs when a substance damages the skin barrier or triggers an allergic reaction.

Triggers differ based on the type:

Irritant contact dermatitis triggers:

• Acids or alkalis
• Cleaning agents or industrial chemicals
• Frequent handwashing or use of alcohol-based sanitisers
• Prolonged exposure to water (“Wet work”)

Allergic contact dermatitis triggers:

• Fragrances or preservatives in skincare products
• Hair dyes (paraphenylenediamine)
• Nickel, often found in jewellery, watches or buttons
• Certain plants, such as poison ivy or mango skin
• Rubber or natural latex

What are the signs and symptoms of Contact Dermatitis?

The signs and symptoms of this condition vary based on the severity and duration of exposure.

They generally fall into two categories:

Acute Symptoms – short-term or sudden reactions

• Blistering or oozing – common in severe or rapid-onsetsudden reactions
• Itching or burning –this can be intense and uncomfortable
• Redness (discolouration) – affected skin may look red, pink or darker depending on your skin tone
• Swelling and inflammation – especially with allergic reactions

Chronic Symptoms – long-term or repeated exposure

• Dry, scaly skin – it may feel rough, cracked or flaky, especially on the hands or feet
• Thickened skin (lichenification) – caused by repeated scratching or rubbing over time

Who is at risk of Contact Dermatitis in Singapore?

The combination of Singapore’s high humidity, frequent handwashing, and the widespread use of skincare and cosmetic products makes skin allergy a common issue in Singapore. However, some groups of people are more likely to develop this condition due to their skin type, lifestyle, occupation or medical history.

Those at higher risk include:

• Age-related vulnerability — this condition can affect people of all ages, but different age groups tend to have different triggers, such as:
  • Infants and toddlers – their skin are more sensitive and easily irritated by certain skincare ingredients
  • Young adults – often develop reactions from cosmetics, hair products or grooming items
  • Middle-aged adults – they tend to be more exposed to workplace irritants
  • Older adults – their skin are thinner and drier, which increases skin vulnerability
• Ethnicity — while skin allergy affects all ethnicities, Asian skin are more prone to post-inflammatory hyperpigmentation, leading to longer-lasting discolouration if not promptly treated.
• History of eczema or allergies — individuals with a history of eczema, asthma or allergic rhinitis (atopic conditions) are more prone to allergic contact dermatitis. This is due to a hyper-reactive immune system.
• Sensitive or dry skin — a naturally weakened skin barrier makes both irritant and allergic contact dermatitis more likely. This is seen especially in older adults and infants.
• Environmental exposures — common triggers include nickel (in jewellery or mobile devices), latex, fragranced skincare products, and tropical plants (like mango skin).
• Frequent hand hygiene —repeated hand washing, use of soaps or alcohol-based sanitisers and prolonged glove use can disrupt the skin barrier. This leads to irritant contact dermatitis, especially without regular moisturising.
• Occupational exposure — healthcare workers, cleaners, hairdressers and chefs who are regularly exposed to water, chemicals or allergens have an increased risk of developing the condition.

How is Contact Dermatitis diagnosed?

As there is no single definitive test, diagnosing skin allergy relies on a combination of methods:

• Medical history — a dermatologist will ask about the onset, duration and pattern of your symptoms. This includes occupational and domestic exposures, skincare routines, personal care products, and any history of eczema, asthma or allergic rhinitis.
• Skin examination — a thorough  visual inspection helps assess the distribution, shape and features of the rash. This allows differentiation from conditions like psoriasis, fungal infections or eczema.
• Patch testing — this is a key diagnostic tool when allergic contact dermatitis is suspected. Small amounts of potential allergens are applied to the skin (usually on the back) under adhesive patches and monitored over 48 to 72 hours for delayed hypersensitivity reactions.
• Skin swabs or biopsies — these are occasionally performed if there are signs of secondary infection (such as oozing or crusting) or if the rash does not improve with standard treatment. A skin biopsy may help confirm the diagnosis or rule out other skin diseases.

What are the treatment options for Contact Dermatitis in Singapore?

An effective treatment for skin allergy focuses on relieving inflammation, repairing the skin barrier, and preventing further exposure to irritants or allergens. Treatment depends on the type, severity and recurrence.

Allergen and Irritant Identification 

• Avoidance strategies – patients are advised to avoid the specific substance once it is identified, such as changing skincare products or adjusting workplace exposures.

Medications

• Topical corticosteroids – they are first-line treatments with potency depending on the affected area. Long-term use should be avoided to prevent skin thinning.
• Topical calcineurin inhibitors – medications like tacrolimus or pimecrolimus are useful in sensitive areas or for longer-term control without the side effects of steroids. They modulate the immune response without causing skin thinning.
• Oral corticosteroids – prescribed for severe, widespread allergic reactions that are typically given for short courses due to potential side effects.
• Topical or oral antibiotics – if there are signs of bacterial infection such as crusting, oozing or increasing redness, antibiotics like topical fusidic acid or oral penicillin/ cephalosporins may be needed.

Skin Barrier Care

• Barrier creams and protective gloves – especially important in occupational settings. These provide a physical layer against irritants, particularly for individuals in healthcare, food handling or cleaning industries.
• Emollients and moisturisers – used liberally throughout the day to maintain skin hydration. Thick creams or ointments are preferred over lotions, especially after washing hands or bathing.
• Soap substitutes and gentle cleansers – non-foaming, fragrance-free cleansers help cleanse the skin gently without stripping protective oils.

Lifestyle Modifications

• Climate considerations – in humid regions like Singapore, choosing breathable clothing and managing sweat can help reduce irritation and friction.
• Hand hygiene practices – use lukewarm water and non-soap cleansers. Apply moisturiser immediately after washing. For those who wash their hands frequently, alternating gloves and using barrier creams can help protect the skin.
• Occupational adjustments – protective equipment or role modifications may be needed to reduce exposure to triggers in severe or persistent cases.

Summary

We understand how frustrating and uncomfortable it can be, especially when it affects your daily routine, work or confidence. Whether it is caused by frequent handwashing, skincare products or workplace exposure, the persistent irritation may affect daily activities and well-being.

The good news is that the condition is highly manageable. With the right diagnosis, simple skincare habits and personalised guidance, most people experience significant improvement. If your rashes keep returning or are not getting better, a consultation with a dermatologist at Dermatology Collective can help identify your specific triggers and start you on a treatment plan that works.

Get in touch with us today to begin your journey towards stronger, healthier skin.