Contact Dermatitis- Patch Testing Techniques

Contact Dermatitis

If you have ever experienced dry, red or itchy skin, you know how frustrating and debilitating it can be.

Whether it is a small rash on your face or a rash covering your entire body, it is possibly due to Contact Dermatitis.

 

We recently attended the Melbourne Dermatology Conference in May 2019 and the Skin and Cancer Foundation patch test training day, where we got to learn more interesting information about Allergic Contact Dermatitis and refine our skill in patch testing. Patch testing is the way forward in allowing out patients to find out what they are allergic to!

Allergic Contact dermatitis (also called contact eczema) refers to a group of skin disorders in which the skin reaction is due to direct contact with the causative agent. The term dermatitis implies that the outside layers of skin are affected. It can be acute (a single episode) or chronic (persistent). Dermatitis is nearly always itchy.

Allergic Contact dermatitis is the most common cause of occupational skin disease, and is particularly common in cleaners, healthcare workers, food handlers and hairdressers due to the sheer numbers of chemicals these professionals come into contact with on a daily basis with work.

What does it look like?

  • Redness (erythema)
  • Blisters that are small (vesicles) or large (bullae)
  • Swelling (oedema)
  • Dryness or scaling
  • Cracks (fissuring)
  • Lichenification (thickened, lined skin)
  • Pigmentation increased (hyperpigmentation) or reduced (hypopigmentation).

What will patients complain of?

Itchy, dry skin in a patterned distribution. So for example, with hair dye allergy, it will come up as a scalp rash but also a rash and swelling around the eyes. For nail cosmetics allergy, this may come up as a rash around the eyelids. For allergies to clothing textiles and dyes, the rash might outline the exact pattern of the clothing (eg socks, gloves etc).

How is the diagnosis for contact dermatitis made?

The dermatologist will take you through a thorough consult, taking down all history carefully and making note of all possible irritants and exposures. Once the dermatologist can clearly identify what is causing your rash, it is important to avoid direct contact with those irritants.

  • Avoid soap – use a pH-balanced cleanser suitable for sensitive skin
  • Dry skin carefully after washing

The rash can be treated with a short course of topical corticosteroid steroid. Apply emollients/moisturiser frequently while the rash is active and for some weeks afterwards as the normal skin barrier function is restored. Severe contact dermatitis may be treated with a short course of systemic corticosteroids, e.g. oral prednisone. Occasionally, for chronic contact dermatitis, phototherapy may be tried, or immunosuppressive agents such as methotrexate,ciclosporin or azathioprine may be prescribed.

 

Patch Testing

If the dermatologist can’t determine the exact cause of your dermatitis straight off sometimes we have to do a bit of detective work to get to a diagnosis, that’s where patch testing comes in!

 

Patch testing is a simple and non-invasive way of detecting what your body is allergic or reacting too. We are looking for a diagnosis to help narrow down how your skin reacts to certain stimulants when placed on your skin for a certain amount of time. The first appointment will be a history taking exercise and thorough examination to narrow down potential allergens.

 

After the allergens for patch testing are then ordered (which can take 1-2 weeks), we will bring you back for an appointment to place allergen strips on your back. You will then come back 48 hours later to have your first reading; the second reading will be a further 48hrs to see if you have had a late reaction. Hence, we find doing a Monday-Wednesday-Friday cycle the most efficient way of conducting the readings.

 

We do a very thorough testing and can test for a range of different irritants such as

-Sunscreens                     -Airborne Allergies                -Tapes/dressings

-Fragrances                     -Textile dyes                          -Metals/nickel

-Cosmetics                     -Corticosteroids                     –Car Fragrance/air fresheners

-Hairdressing products

 

Once we get a diagnosis, we can then look at removing these from your routine and start treatment for you. These results can be positive OR negative, all leading to a diagnosis. If not allergic contact dermatitis then possibly irritant contact dermatitis could be the diagnosis.

Just remember to be patient, it is a process to get to a diagnosis, but it can be life changing once we get a diagnosis for you!

To start your skin journey and for patch testing appointments with one of our dermatologists please call our clinic on 9039 5644.

IN THE MEDIA – Rosehip Oil

Read Dr Hope Dinh’s full interview with the Australian Women’s Weekly (May 2019 issue) on her thoughts on Rosehip oil and is it as good as it smells?!

Here is the interview excerpt with Dr Dinh (in Q & A form!)

What solid benefits do they have for skin?

Rose hip oil is good for pigmentation issues, scars and fine lines. This is because in addition to nourishing and moisturising omega-6 essential fatty acids and antioxidants, it also contains vitamins A and C which help to increase cell turn-over; producing a retinol-like effect.

Plant oils are commonly used for cosmetic purposes and have been found to have many benefits . Rosehip oil is rich in antioxidants including Vit C, E, B and abundant in unsaturated fatty acids (linoleic) which are shown to reduce transepidermal water loss (TEWL) and reduce irritation through barrier repair.

Rosehip oil can also help with acne due to its high concentration of linoleic acid, allowing for an anti-inflammatory effect.

Are there any drawbacks (from my understanding so far, the fragrance component of rose oil is irritating and inflammatory)?

Fragrances in general are high on the list of allergic contact dermatitis.  Rosehip oil is widely available as a pure oil and so irritation from fragrances as such is not necessarily an issue.  Care should be taken in sensitive skin when using products containing Rosehip oil as other additives can cause irritation, particularly because of the high concentration of antioxidants such as Vitamin C and Tocopherol (Vitamin E), can be an allergen.

Anything used in high quantities and without regard to how the individual persons skin is reacting can potentially cause irritant contact dermatitis. You don’t necessarily have to use it daily to reap the benefits. By using the oil less frequently, there may be less risk of skin irritation for those who are prone to sensitivity.  End message I give most of my patients is to start at low frequency application e.g. every 2-3 days and then after a while can slowly titrate up frequency, carefully looking for irritation or other side effects.

When a skin boil is more serious….could this be hidradenitis?

Hidradenitis Suppurativa (HS) – the latest information from the recent Melbourne Dermatology Conference May 2019.

Every year the Australasian College of Dermatologists holds an annual scientific meeting to update us all on the latest advancements in the diagnosis and management of dermatologic diseases. This year it was held in Melbourne (YES – my home town!). After 4 days of absorbing all this amazing information, my head is bursting with ideas for managing our existing patients. One session that really got my attention was the hidradenitis suppurativa lecture. Mainly under-diagnosed and sub-optimally managed, the prevalence of this condition is 0.67% (so, it’s more common than you think!). It was pleasing to hear that dermatologists lead the list of the medical specialists diagnosing this condition but there is STILL a LONG delay of MANY YEARS to patients being formally diagnosed with this condition.

WHY?

There can be many factors leading to diagnosis delay including embarrassment from the patient about the condition and so they never speak up about it, sub-optimal education of other medical specialties about the condition, patients thinking it is just a “simple boil” in the groin etc  ……in order to diagnose HS earlier, the public needs to be more aware that a condition like HS even EXISTS…..

We really should be asking our patients –Do you suffer from sore painful lumps or boils under your armpits or groin area?? Do you mind if I have a look? As it could be hidradenitis suppurativa.”

“SEEK and YOU WILL FIND”

_____________________________________________________________________________

Hidradenitis suppurativa is an inflammatory skin disease that affects gland-bearing skin in the underarms, in the groin, and under the breasts. It is characterised by recurrent boil-like nodules and abscesses that culminate in pus-like discharge, difficult-to-heal open wounds (sinuses) and scarring. Hidradenitis suppurativa also has significant psychological impact and many patients suffer from impairment of body image, depression and anxiety.

Hidradenitis often starts at puberty, it is most active between the ages of 20 and 40 years, and in women, can resolve at menopause. It is three times more common in females than in males. Risk factors include:

  • Other family members with hidradenitis suppurativa
  • Obesity and insulin resistance/metabolic syndrome
  • Cigarette smoking
  • Acne
  • Inflammatory bowel disease
  • Rare autoinflammatory syndromes

Signs and Symptoms

HS can affect single or multiple areas in the armpits, neck, sub mammary area, groin and inner thighs. Anogenital involvement most commonly affects the groin and vulva (in females), sides of the scrotum (in males), buttocks and perianal folds.

  • Open and closed comedones (white heads and blackheads)
  • Painful firm papules, larger nodules and pleated ridges
  • Pustules, fluctuant pseudocysts and abscesses
  • Draining sinuses (like “tunnels” under the skin) linking inflammatory lesions
  • Thick (hypertrophic) scarring

Hidradenitis can be associated with inflammatory bowel disease and so it is important for your dermatologist to also consider screening for your risk of this condition too. HS can also be associated with acne, psoriasis and hirsutism.

General measures you can do at home

  • Loose fitting clothing
  • Avoiding too much friction in affected areas (being careful with the types of exercise pursued). It may be worth considering the High Intensity Workout regimes which get your blood pumping quickly but minimise too much frictional irritation.
  • Reduction in weight (to lead to decreased friction in the skin fold areas); dietician advice may be helpful
  • Daily un-fragranced antiperspirants
  • If prone to secondary infection, wash with antiseptics or use dilute bleach baths
  • Apply simple dressings to draining sinuses
  • Analgesics, such as paracetamol (acetaminophen), for pain control
  • Seek help to manage co-existing mood issues such as anxiety and depression
  • Seek GP advice about weight loss, mood issues, quitting smoking etc. Also GPs can act and possibly come up with Team Care Arrangements which then allow patients to access some allied health services for FREE (like dietician consults and psychological support).
  • Join a support group so you can receive tips and support from people who going through the EXACT same issues as you!

We are here to help you manage your disease!

The dermatologist may prescribe local therapies such as –

  • anti-septic washes (such as Phisohex or Chlorhexidine),
  • antibiotic cream (such as Clindamycin 1% cream),
  • injections of steroid solution into the inflamed lumps.
  • Topical vitamin A creams (retinoids) to help unblock the blackheads and whiteheads

Oral medications include –

  • Oral contraceptive pill or hormonal treatments such as spironolactone (for females).
  • Oral antibiotics to clear any infection and reduce inflammation (must be taken for a few months to see the outcome).
  • Vitamin A tablets such as isotretinoin or acitretin
  • Metformin (a diabetic medication) which can help with the insulin resistance pathway which can drive HS
  • Oral immunosuppression tablets

Injectables

  • There are the new injectable “biologic” medications which have recently been approved under the PBS for eligible patients with hidradenitis.

Surgery

  • Simple surgery that can be done at the dermatologist without general anaesthetic. This is the technique of de-roofing the very inflamed lesions to allow for healing.
  • More complex surgery can be done in hospital via Plastics and usually done with consultation with the Dermatology Team.

Key points to remember

– Get the correct diagnosis from a professional such as a dermatologist EARLY, don’t mistake it just as a pimple

– Early treatment can mean less chance of scarring

– There are simple home measures you can do to prevent them from flaring

– With appropriate treatment you can stop this disease from returning

Want to know more? Here are some online resources

https://www.hs-online.com.au

https://www.dermnetnz.org/topics/hidradenitis-suppurativa/

http://anzvs.org/patient-information/hidradenitis-suppurativa/

http://hidradenitissuppurativasupportgroup.org/

Treatment options for viral warts

Warts are growths on the surface of the skin caused by human papillomavirus (HPV). While usually benign, these pesky bumps are in fact contagious.

Warts can be stubborn things to get rid of and can sometimes take months to resolve. You may have visited your GP for a wart where just freezing the wart can be an effective treatment. If however it doesn’t go away with a couple of freezing treatments, you may need to see a dermatologist to receive different treatment. The quicker you get on to the wart the easiest it will be to remove it.

Warts are contagious and you are more likely to pick them up in warm moist areas such as swimming pools or public showers. People who sweat more may be more prone and it is very common to see in children as they may pick them up at school from others.

Treatment in our clinic can involve different strength topicals that illicit the immune system to, in a sense, ‘’wake up’’ and shock the immune system to expel the viral skin lesion. The immune system will then start to fight the virus from the inside; the treatments can also attack the wart from the outside.

The topical solutions we use on the wart may provoke a blister to develop and this will typically begin to heal within a week. Once the blister resolves, so does that wart!

Sometimes, with in-clinic medication, only one or two treatments are necessary. We will also give you home treatment to do in the weeks after, to make sure the wart doesn’t have a chance to grow back! As we know, warts are stubborn little things and need to be attacked quite regularly to stop spreading and remove them for good!

Helpful hints to avoid getting warts!

As warts thrive in hot/sweaty conditions, if you sweat a lot, wear cool clothing/change socks frequently etc. Baby powder can be an option to put on the feet before socks, to soak up any excess sweat.

Wear thongs in public showers to avoid picking up viral warts

If you do have some warts, avoid picking/scratching them as they can directly spread via this method! Call us on 03 9039 5644 for an appointment to clear those warts for good!

How to choose a sunscreen – SPF myths and misconceptions

 

 

UV radiation from sun exposure is the greatest risk factor for developing skin cancer.  Here in Australia dangerous melanomas are the third most common types of cancer diagnosed. 
Simple sun protection measures including daily use of a broad-spectrum sunscreen can reduce you and your family’s risk of developing skin cancers later in life.  If this is not compelling enough to encourage you to protect yourself, see our earlier post on UV photo ageing.  Wrinkles! Argghhhh

 

 
Our Cosmetic Nurse Kristie breaks down the jargon and myths surrounding sunscreen use.
 
“What does SPF even mean?”

SPF is an acronym for Sun Protection Factor and is a measurement of how effectively a sunscreen will protect the skin from UVB rays (it does not measure UVA, this is important! More on this later).

Confusingly, it talks about time e.g. if it takes 10 minutes to burn without cream, applying an SPF 15 means it will take approximately 150 minutes to burn (a factor of 15 times longer).  THIS DOES NOT MEAN YOU CAN STAY IN THE SUN LONGER OR THAT YOU CAN GO LONGER WITHOUT REAPPLYING.  Sunscreen should always be reapplied after 2 hours to ensure continuous protection.

Misleading I know.

“So, what SPF should I be using?”

The SPF (Sun Protection Factor) scale is not linear, in that an SPF 30 is not “twice” as protecting as an SPF 15.  In fact, SPF 15 blocks 93% of UVB rays, SPF 30 blocks 97% of UVB rays and SPF 50 blocks 98% of UVB. The difference from an SPF 15 to SPF 30 is only 4%.

“So why do I need a higher SPF?”

Flip it around and think about what you are letting through.

SPF 15 (93% protection) allows 7 out of 100 photons through. SPF 30 (97% protection) allows 3 out of 100 photons through. That’s twice as many skin damaging photons!

“I don’t need sunscreen because I’m not outdoors?”

Not true.  UVA, which is responsible for ageing of the skin and contributes to skin cancer formation can pass through glass.  And incidental sun adds up.  Walking to the train, sitting in the window, driving.  So you don’t need to be “outside” to be exposed.

I always tell people to invest in a broad-spectrum product containing SPF 30-50 that they like enough to wear every single day.

Why?

The Anti-Cancer council recommends that sunscreen is required on days when the UV index is 3 or greater (typically in the warmer months between 11-3 pm), which is the threshold at which the UV is strong enough to damage the skin.  HOWEVER, we are creatures of habit and I find in myself and many of my patients that if your skincare routine is not just that, a ROUTINE, then things go to the wayside and before you know it, it’s mid-September, 12 noon and you find yourself in a café without sun protection!

A broad-spectrum sunscreen is important as SPF measures only UVB and we know UVA is a big culprit in causing skin damage.  A broad-spectrum sunscreen will protect against both UVA and UVB.

“What is the UV index?”

It’s “sciency”.  There are a LOT of variables that can influence the amount of UV reaching us.  But scientists are all over this and we highly recommend everyone download the Sun Smart App which will tell you what the maximum UV index for the day is forecast to be and when it is at its highest.

Thank you science!

“Do I need to reapply?”

Yes. All sunscreens need to be reapplied after two hours to maintain their SPF role. Are you going to reapply your sunscreen over your makeup at lunchtime in the middle of winter when you’re in the office? Probably not. And that’s ok.

1/ Because the UV index is low then

2/ Most of the damage from UV comes from accumulated exposure. Our skin is like a data bank for sun damage! So having your base SPF on for incidental sun when you leave the house helps reduce your lifetime UV exposure and associated damage. Unless your office desk is next to a window. Then see my earlier point about UVA passing through glass.

The reason to reapply is often unclear?  Is it wiping off? Does it have a time-limit of efficacy? Does it breakdown?

The answer is all of those things.  You will touch, rub, wipe, smear, and remove some of your SPF protection without noticing.  If you are sweating, exercising, swimming, etc we are pretty clear on the fact that your sunscreen will not withstand that.  Reapply.

Some chemical sunscreens do break down when exposed to sunlight. This is less of a concern with mineral (zinc or titanium oxide) sunscreens but this does mean that if you are outdoors, in the sun, your sunscreen DOES have a lifespan and it DOES breakdown.  It lends merit the argument that if you are in an office, away from all windows and will have minimal incidental sun (and don’t touch your face AT ALL) then your sunscreen MAY last longer.  I would definitely encourage you to reapply if you are planning on spending significant time (>1 hour) outdoors.

“I heard Nanoparticles were dangerous?”

They’re not.  The worry here was that the smaller nanoparticles which allow higher concentrations of our physical blocks containing zinc and titanium dioxide to be used in creams and still feel lovely and light on the skin were able to be absorbed though the skin and enter our bodies and cause harm.

This is not proven. The current evidence is that these particles do not penetrate the skin and remain on the surface as intended so the risk is negligible.  If applied to damaged or compromised skin there can be some penetration of the outermost layer of skin but they are not absorbed systemically (i.e. they don’t circulate throughout the body).   Be more concerned about inhaling spray sunscreens! Stay away from light sprays that flow with the wind and avoid these on the face.

“But what about Vitamin D?”

According to the Cancer Council sensible sun protection does not put people at risk of vitamin D deficiency and several studies have shown that sunscreen use has minimal impact on Vitamin D levels over time.  Incidental exposure, a few minutes most days is all most people require for adequate Vitamin D production.  If you are deficient in Vitamin D increasing UV exposure is not recommended and you should speak with your GP regarding supplementation.

We hope this clears up some common excuses people use for NOT applying sunscreen every day.  There are no excuses!  We KNOW skin cancer is directly related to UV exposure and we KNOW sunscreen protects us from this.  

 

There are so many nice, easy-to-use sunscreens available these days for every budget.  If you need a hand choosing one, call us today on 9039 5644 and book a consultation with our Cosmetic Nurse Kristie and we will get you on the right track.