Something changed. A new shampoo, a different pair of gloves at work, a necklace you were given, a relaxer at a salon you hadn’t used before. And now a patch of your skin is red, itchy, dry or blistering — and it isn’t settling.
Contact dermatitis is your skin reacting to something it has touched. Which means, unlike most skin conditions, it has a cause you can actually remove.
The hard part is working out what that cause is. That’s what this page is about.
When your skin is reacting to something it’s touching
Contact dermatitis shows up as:
- Redness — which on deeper skin tones often reads as darker, purplish or greyish rather than obviously red
- Itching, sometimes intense
- Dryness, scaling or cracking
- Small blisters or weeping in more acute reactions
- Burning or stinging rather than itch, in some cases
- Thickened, leathery skin where it has been going on for months
The single most useful clue is that it appears where the thing touched you — and often in the exact shape of the object. A band around the wrist. A line under a necklace. The hairline and the tops of the ears after a dye. A rectangle where a plaster was.
The two kinds, and why the difference matters
They look similar. They are not the same thing, and treating them the same way is why some people never get better.
| Irritant | Allergic | |
|---|---|---|
| What’s happening | The substance damages the skin barrier directly | Your immune system has become sensitised to it |
| Who it affects | Anyone, given enough exposure | Only people who have become allergic |
| How fast | Can be immediate, or build over weeks | 24–72 hours after contact |
| How much is needed | Usually repeated or prolonged contact | A tiny amount is enough |
| Where it appears | Where contact happened | Where contact happened — and sometimes beyond |
| Common examples | Soap, water, detergent, solvents | Hair dye, nickel, fragrance, preservatives, rubber |
Irritant contact dermatitis
This is the more common of the two — roughly the majority of cases. Something is physically stripping your skin barrier. Frequent handwashing. Detergent. Cleaning chemicals. Constantly wet hands.
No allergy involved. Anyone would react, given enough exposure. The fix is protecting and repairing the barrier, and reducing the exposure.
Allergic contact dermatitis
Here your immune system has learned to react to a specific substance. Once that happens, it is generally permanent, and it takes only a trace to set off a reaction.
The tricky part is the delay. The rash appears one to three days after contact, so people rarely connect the two. You dye your hair on Saturday and blame something else entirely by Tuesday.
Where it appears tells us a lot
| Where the rash is | What we’d suspect first |
|---|---|
| Hairline, ears, back of neck, forehead | Hair dye, relaxer, or another scalp product |
| Palms and finger webs | Occupational — soaps, gloves, wet work, chemicals |
| Earlobes, wrist, belly button, under a watch | Nickel in jewellery, buckles or fasteners |
| Eyelids | Cosmetics, nail products transferred by touch, airborne substances |
| Face and neck, spreading | Fragrance in perfume, lotion or laundry products |
| Feet | Rubber accelerators or dyes in footwear |
| Under clothing seams or elastic | Textile dye, rubber in elastic |
Eyelids deserve a special mention: they are the thinnest skin on the body and often react to something your hands touched and transferred there — nail polish being a classic.
The usual culprits in Nairobi
Hair products, relaxers and dye
This is the big one locally, and it doesn’t get talked about enough.
Paraphenylenediamine (PPD) in permanent hair dye is one of the most common contact allergens worldwide. Reactions range from itching at the hairline to significant swelling of the face and scalp. Once you are sensitised to PPD, you are sensitised for life — and it cross-reacts with some other chemicals, including certain black henna preparations.
Chemical relaxers are strongly alkaline and are primarily an irritant problem — scalp burning, sores, and in repeated use, damage that contributes to hair loss. If relaxer use is affecting your scalp and hair, that connects to our hair loss treatment page too.
Salon professionals are affected as often as clients. If you work in a salon and your hands are cracked and sore, this page is about you.
Hands, work and water
Occupational hand dermatitis is common and genuinely threatens people’s ability to work. Most at risk: hairdressers and barbers, cleaners, healthcare and lab staff, mechanics, caterers and food handlers.
It usually starts as dryness between the fingers and progresses to cracking and pain. Left alone, it can become chronic and much harder to reverse — which is why early treatment matters more than people assume.
Jewellery and nickel
Nickel is the classic allergen: earlobes, the back of a watch, a belt buckle, a bra hook, the stud on a pair of jeans. Reactions often begin after ear piercing. Once identified, it’s very manageable — you avoid nickel-containing items.
Cosmetics, fragrance and preservatives
Fragrance and preservatives are the usual offenders, not the “active” ingredient people suspect. “Unscented” is not the same as “fragrance-free” — some unscented products contain masking fragrance.
Skin-lightening products
Many lightening creams contain ingredients that irritate or sensitise skin, and some contain potent steroids or other agents that cause distinct problems of their own. If a lightening product has caused a reaction, the dermatitis and the pigmentation change are two separate issues needing two different approaches.
Our hyperpigmentation and melasma treatment page covers the pigmentation side in detail.
Finding the culprit: how we work it out
Three steps.
- A detailed history. What is new, what you use daily, what you do for work, what your hobbies are. This alone identifies the cause in a large share of cases.
- Reading the pattern. Where it is, its shape, and how it behaves over the week tells us a great deal — including whether we’re looking at irritant or allergic.
- Patch testing, where an allergic cause is likely but not obvious. Small amounts of standard allergens are applied to the back under adhesive patches and read at 48 and 96 hours. It’s the definitive test for allergic contact dermatitis.
Patch testing has limited availability in Kenya. Where it’s indicated, we’ll discuss what’s realistically accessible and arrange it where we can. Where it isn’t practical, a structured elimination approach can still identify the cause — it just takes longer and needs discipline from you.
How contact dermatitis is treated
Remove the cause. Everything else is secondary. There is no treatment that outruns ongoing exposure.
Settle the inflammation. Topical steroids, at a strength matched to the site — much gentler on the face and eyelids than on palms. Used properly for a defined period, they are safe and effective. The problems people have with steroid creams come from indefinite unsupervised use, not from a correct course.
Repair the barrier. Emollients, generously and regularly, especially for irritant hand dermatitis. This is not optional extra advice — it is a substantial part of the treatment.
Protect going forward. Glove choice matters and is often wrong. Latex is itself a common allergen; for wet work, cotton liners under waterproof gloves work far better than gloves alone. For hair professionals, correct glove technique is genuinely career-preserving.
Treat any infection. Scratched, cracked skin gets infected. See fungal and bacterial skin infections.
For severe or widespread cases, a short oral course may be needed. Where the diagnosis is uncertain — because some rashes mimic dermatitis — a skin biopsy clarifies things.
What it leaves behind on deeper skin
Once the rash settles, the skin often isn’t finished.
Post-inflammatory hyperpigmentation — darker patches where the inflammation was — is more pronounced and more persistent on deeper skin tones. Occasionally you get the opposite, a lighter patch.
This is why we treat contact dermatitis promptly rather than waiting it out. The longer the inflammation runs, the more marking it leaves, and that marking can take many months to fade. Plenty of people arrive far more troubled by the dark patch than they ever were by the original rash.
What to do between now and your appointment
You don’t have to wait passively. A few things genuinely help, and one of them makes your appointment substantially more useful.
Start a short list. Write down everything that touches the affected area — soaps, creams, cosmetics, hair products, detergents, gloves, jewellery, work materials. Note anything that changed in the six weeks before the rash appeared. Most diagnoses come out of this list, and people almost never remember it accurately on the spot.
Photograph it. Rashes have an inconvenient habit of improving on the morning of the appointment. A photo taken at its worst is real diagnostic information.
Simplify, don’t experiment. Strip back to a plain, fragrance-free wash and a plain emollient. Stop applying anything new. Adding a fourth product to calm a reaction to the other three is the most common mistake here.
Bring the packaging. Not the product name from memory — the actual bottles, or clear photographs of the ingredient lists. Ingredient lists are where the answer usually is, and brand names change formulations without telling anyone.
Don’t scratch, however tempting. Scratching thickens the skin, breaks the barrier further and invites infection, and on deeper skin tones it deepens the mark left behind.
Don’t use someone else’s steroid cream. Strength matters enormously by body site, and a strong steroid meant for someone’s elbow can do real damage on a face or eyelid.
Is this contact dermatitis or eczema?
A fair question, because they can look identical.
Atopic eczema is constitutional — it tends to run in families alongside asthma and hay fever, usually starts in childhood, and appears in characteristic places like elbow creases and behind the knees. It comes from how your skin is built.
Contact dermatitis comes from outside. It appears where something touched you, often in a revealing shape, and it can start at any age — including in someone who has never had a skin problem in their life.
The two also overlap: people with eczema have more fragile skin barriers and are more prone to irritant reactions. If you have long-standing eczema that has recently become harder to control, a new contact trigger is well worth investigating.
Our eczema and dermatitis treatment page covers the atopic side.
What your first appointment looks like
- We take a proper history — this is where most of the answer comes from.
- We examine the pattern, not just the rash.
- We settle the acute inflammation so you get relief quickly.
- We build an avoidance plan with specifics — products, materials, and what to use instead.
- We arrange patch testing if it’s indicated and accessible.
- We review, because identifying a trigger is often iterative.
Appointments run from 8:30am to 5:00pm on weekdays, and 9:00am to 4:00pm on Saturdays.
Getting to the clinic
We are on the 2nd floor of Landmark Plaza, Argwings Kodhek Road, on the Hurlingham edge of Upper Hill.
- Dermatologist in Upper Hill
- Dermatologist in Kilimani
- Dermatologist in Westlands
- Every area we serve
Frequently asked questions
How long does contact dermatitis take to clear? Once the cause is removed and treatment started, most cases settle within two to four weeks. Hands are slower, because you keep using them. Any darkening left behind takes longer — often several months.
Can contact dermatitis appear suddenly to something I’ve used for years? Yes, and this surprises people constantly. Allergic sensitisation develops over time. Years of uneventful use then a reaction is a completely typical story.
Is it contagious? No.
Can I keep dyeing my hair if I’ve reacted to dye? If you’re allergic to PPD, permanent dyes containing it are out — the next reaction is often worse. There are alternatives, but they need choosing carefully, and “natural” or “herbal” labelling is no guarantee. Bring the product to your appointment.
Do I definitely need patch testing? No. Many cases are solved from history and pattern alone. Testing is for when an allergic cause is likely but the culprit isn’t obvious.
Are steroid creams safe? Used at the right strength, on the right site, for a defined period — yes. Problems come from prolonged unsupervised use, particularly of strong steroids on the face. That’s precisely why the prescription should come from someone who examined you.
My hands crack every dry season. Is that this? Possibly irritant hand dermatitis, made worse by weather and handwashing. It’s worth assessing rather than living with — chronic hand dermatitis is much harder to reverse than early hand dermatitis.
Will it leave dark marks? Often, on deeper skin tones. Treating early limits it, and the marking can itself be treated once the dermatitis has settled.
Can children get it? Yes — commonly from cosmetics, nickel, or products used on their skin. See paediatric dermatology.
Book an appointment
If your skin is reacting to something and you can’t work out what, that is exactly the problem a dermatologist is for. Bring the products you suspect — including the packaging.
We open at 8:30am Monday to Friday and 9:00am to 4:00pm on Saturdays.
Landmark Plaza, 2nd Floor, Argwings Kodhek Rd, Nairobi
Call or WhatsApp 0728 566990
info@skinbydrnancy.com
Book an appointment or browse all dermatology services.