[20] Dermatitis Flashcards
What is dermatitis?
Dermatitis, also known as eczema, is a group of diseases that result in inflammation of the skin
What is dermatitis characterised by?
- Itchiness
- Red skin
- Rash
How much of the skin is affected in dermatitis?
Can range from a small amount to the whole body
What are the types of dermatitis?
- Atopic dermatitis
- Allergic contact dermatitis
- Irritant contact dermatitis
- Stasis dermatitis
What is atopic dermatitis?
An inflammation of the skin, that tends to flare up from time to time. It can range from mild to severe
When does atopic dermatitis usually start?
In early childhood
What proportion of children with atopic dermatitis grow out of it by their mid teens?
About 2/3
What causes atopic dermatitis?
The exact cause is unknown, although there is some evidence of genetic, environmental, and immunologic factors
What suggest a genetic component to atopic dermatitis?
- Most people with atopic dermatitis have a family history of atopy
- About 30% of people with atopic dermatitis have a mutation in the gene for the production of filaggrin
What is the role of filaggrin?
It plays an important role in keeping the skin surface slightly acidic, hence giving it anti-microbial effects
What environmental factors may be involved in atopic dermatitis?
- Hygiene hypothesis
- Sensitisation to foods
- Consumption of hard water
What is the hygiene hypothesis?
A theory that children who are raised in a sanitary environment are more likely to develop allergies - there is some support for this theory with regard to atopic dermatitis
What are the symptoms of atopic dermatitis?
- Dry skin
- Some areas of the skin become red and inflamed. The inflamed skin is itchy, and may become blistered and weepy
What areas of skin are most commonly affected in atopic dermatitis?
The areas next to skin creases, such as the front of the elbows and wrists, backs of knees, and around the neck, however any area of skin might be affected
What typically happens to inflamed areas of skin in atopic dermatitis?
They tend to flare up from time to time, and then settle down
How do flare-ups of atopic dermatitis vary?
The severity and duration of flare-ups varies from person to person, and from time to time in the same person
What might a flare-up cause in mild cases?
One or two small patches of inflammation
What might a flare-up cause in severe cases?
Inflammation covering many areas of skin that lasts for several weeks or more
On what basis is atopic dermatitis diagnosed?
Clinically
What are the UK diagnostic criteria of atopic dermatitis?
The person must have itchy skin, or evidence of rubbing/scratching, plus 3 or more of;
- Involvement of skin creases
- History of asthma or allergic rhinitis
- Symptoms began before age 2 (if patient >4 years old)
- History of dry skin (within past year)
- Dermatitis visible on flexural surfaces (patient >4), or on cheeks, forehead, and extensor surfaces (patients <4)
How often should you assess atopic dermatitis?
At every consultation
Why is it important to assess atopic dermatitis at every consultation?
In order to determine the most approrpiate treatment
How should assessment of severity of atopic dermatitis be done?
Examine all areas of affected skin, and ask about itching
What can dermatitis be categorised as, based on severity?
- Clear
- Mild
- Moderate
- Severe
- Infected
What is classified as clear in atopic dermatitis?
Normal skin, no evidence of acute dermatitis
What is classified as mild in atopic dermatitis?
Areas of dry skin, and infrequent itching (with or without small areas of redness)
What is classified as moderate in atopic dermatitis?
Areas of dry skin, frequent itching, and redness
What is classified as severe in atopic dermatitis?
Widespread areas of dry skin, incessant itching, redness, may be extensive skin thickening, bleeding, oozing, cracking, and alteration of pigmentation
What is classified as infected in atopic dermatitis?
Weeping, crusted, pustules, fever, malaise
How is mild atopic dermatitis managed?
- Prescribe generous amounts of emollients, and advise frequent and liberal use
- Consider prescribing a mild topical corticosteroid (such as hydrocortisone 1%) for areas of red skin. Treatment should be continued for 48 hours after flare has been controlled
- Give appropriate information and advice
What information and advice should be given to patients with mild atopic dermatitis?
- How to maintain skin and reduce risk of flares
- Self care advice
- Avoid trigger factors
What are the potential trigger factors of atopic dermatitis?
- Soaps and detergents
- Animals
- Heat
- Synthetic fibres
- House-dust mits
- Stess and habit scratching
- Pregnancy and pre-menstural hormone changes
How is a current flare of moderate atopic dermatitis managed?
- Consider possibility of trigger factors or infection, which can precipitate or worsen a flare
- Prescribe a general amount of emollients, and advise frequent and liberal use
- If the skin is inflamed, prescribe a moderately potent topical corticosteroid, for example betamethasome valerate 0.025% to be used on inflamed areas. Treatment should be continued for 48 hours after falre has improved
- If severe itch or urticarial, consider prescribing one month trial of non-sedating antihistamine
What should preventative treatment be prescribed based on in moderate atopic dermatitis?
The usual severity of the condition between flares
What is the first line option in the prevention of future flares in moderate atopic dermatitis?
A maintenance regime of topical corticosteroids to control areas of skin prone to frequent flares (not recommended for face, genitals, or axilla)
What is the second line option in the prevention of future flares in moderate atopic dermatitis?
Topical calcinneurin inhibitors
What does optimal follow-up time depend on in moderate atopic dermatitis?
A number of factors, such as severity of condition, treatment the person is receiving, and their health/age
How often should emollient use be reviewed in moderate atopic dermatitis?
Annual basis
What is the purpose of annual review of emollient use in moderate atopic dermatitis?
Ensure optimal usage
How often should topical corticosteroid use be reviewed in moderate atopic dermatitis?
Regular review if there is heavy useage, however this is unlikely to be necessary with moderate dermatitis
How often should the use of non-sedating antihistamines be reviewed in moderate atopic dermatitis?
Every 3 months
How is severe atopic dermatitis management?
- Treatment largely the same as for moderate flare, except use a more potent topical corticosteroid on inflamed areas, such as betamethasone valerate 0.1%
- If itching is severe and affecting sleep, consider prescribing short course (maximum 2 weeks) of sedating antihistamine
- If there is severe, extensive dermatitis causing psychological distress, consider prescribing short course of oral corticosteroid
What needs to be done in all people who have had a severe and extensive flare requiring treatment with oral corticosteroids or oral antibiotics?
Need reviewing after course is finished, and consider the need for referral
How is currently infected dermatitis managed when there is extensive areas of infected eczema?
Swab the skin and prescribe an oral antibiotic
What is the first line oral antibiotic in the treatment of extensive infected dermatitis?
Flucloaxicillin
What oral antibiotic is prescribed in extensive infected dermatitis if flucoxacillin is contraindicated (e.g. penicillin allergy) or if there is known resistance?
Erythromycin
What oral antibiotic is prescribed in extensive infected dermatitis if the person has been unable to tolerate erythromycin?
Clarithromycin
What should be done in extensive infected dermatitis if the first line antibiotic is ineffective?
Prescribe an alternative
How is currently infected dermatitis that is localised managed?
Topical antibiotics
How long should topical antibiotics be used for in infected eczema?
No longer than 2 weeks
How are future occurences of infected dermatitis prevented?
- Prescribe new supplies of topical products for use after infection as cleared, and advise the person to discard old products
- Consider the use of topical antiseptic preparation as an adjunct to standard treatment to reduce bacterial load in areas prone to infection
What is contact dermatitis?
An inflammatory skin reaction in response to an external stimulus, acting as either an allergen or an irritant
What are the types of contact dermatitis?
- Allergic contact dermatitis
- Irritant contact dermatitis
What is allergic contact dermatitis?
A type IV delayed hypersensitivity reaction that occurs after sensitisation and subsequent re-exposure to an allergen
What is irritant contact dermatitis?
An inflammatory response that occurs after damage to the skin, usually by chemicals
Is irritant contact dermatitis an allergy?
No, it can occur in any individual significantly exposed to an irritant
Is irritant contact dermatitis acute or chronic?
Can be either
What can the insults causing contact dermatitis be classified into?
Chemical, biological, or physical
How can contact with allergens arise?
- Immersion
- Direct handling of contaminated substances
- From workbenches, tools, or clothing
- Splashing
- Dust from air
Give some common irritants
- Water, especially if hard, chalky, or heavily chlorinated
- Detergents and soaps
- Solvents and abrasives
- Machining oils
- Acids and alkalis, including cement
- Reducing agents and oxidising agents
- Powders, dust, and soil
- Some plants
Give some common allergens
- Cosmetics
- Metals, particularly nickel and coblat in jewellery and chromate in cement
- Topical medications
- Rubber additives
- Textiles
- Epoxy resin adhesives
- Plants
What symptoms do both irritant and allergic contact dermatitis present with?
- Redness
- Vesicles or papules on affected area
- Crusting and scaling of skin
Itching of affected area - Pain or burning sensation from affected area
What features may arise in contact dermatitis with chronic exposure?
- Fissures
- Hyperpigmentation
What are the predominant featues of irritant contact dermatitis?
- Burning
- Stinging
- Soreness
What are the predominant features of allergic contact dermatitis?
- Redness
- Itching
- Scaling
Describe the onset of irritant contact dermatitis?
Within 48 hours, may be immediate
Describe the onset of allergic contact dermatitis?
Delayed onset
Describe the location of the rash in irritant contact dermatitis
Rash only in areas of skin exposed to irritant
Describe the location of the rash in allergic contact dermatitis
Rash may be in areas which have not been in contact with the allergen
Describe the resolution of the rash in irritant contact dermatitis?
Resolution occurs quickly after removal of irritant, typically within 4 days
Describe the resolution of allergic contact dermatitis
Resolution may take longer than irritant contact dermatitis, with or without treatment
What is irritant contact dermatitis commonly associated with?
Atopic eczema
What makes a diagnosis of irritant contact dermatitis more likely?
Exposure to friction, soap, detergents, solvents, or wet work
What is the clinical relevance of the presentation and pattern of skin change in contact dermatitis?
It may give some indication of the likely irritant
What area of the body is most commonly affected with direct contact?
Hands
Where might chemicals on clothing cause contact dermatitis?
- Axillae
- Groin
- Feet
Where are dust irritants most likely to cause contact dermatitis?
Areas where dust might collect, such as collar line, belt line, sock line, or in flexural areas
Where are irritants in vapour/mist most likely to affect?
The face and neck
What investigations are done into contact dermatitis?
In many cases, no investigations will be required, and diagnosis is made based on clinical findings and history.
Some patients may require referral to a specialist clinic for patch testing
What are the indications for referral to a specialist clinic for patch testing in contact dermatitis?
- Severe or recurrent distressing symptoms despite adequate treatment with topical corticosteroids
- Suspicion of contact dermatitis without clear history of exposure
What are the differential diagnoses of contact dermatitis?
- Atopic dermatitis
- Seborrhoiec dermatitis
- Ringworm
- Urticaria
- Psoriasis
- Acute infections, such as cellulitis, impetigo, shingles, and chickenpox
What is the most effective form of management of contact dermatitis?
Avoid the irritant producing the dermatitis, when it has been identified.
When might avoidance of the irritant producing the contact dermatitis be the only treatment required?
In milder cases of recent origin
How long will it take for dermatitis after removal of the irritant in milder cases of recent origin?
Approximately 3 weeks
When can simple emollients be used in the management of contact dermatitis?
When the skin barrier has not been breached
When will contact dermatitis require medication?
In more severe or chronic cases
What medication is used in contact dermatitis?
Topical corticosteroid cream, or a short course of oral corticosteroid for acute, severe episodes
What is the strength and period of use of corticosteroid cream in contact dermatitis adjusted based on?
The severity of the condition
What are the second line options for use in contact dermatitis?
- PUVA treatment
- Ciclosporin
- Azathioprine
These are used for chronic, steroid-resistant dermatitis
What are the complications of contact dermatitis?
Secondary bacterial infection
How does a secondary bacterial infection in contact dermatitis present?
As worsening of the skin condition, or as typical impetigo
