Eczema Flashcards
What is the most common type of eczema?
How common is it?
atopic dermatitis/eczema
it is an inflammatory skin condition with onset commonly during childhood
it presents in 15-20% (1 in 5) children
What is meant by atopy?
atopy is the triad of:
- atopic dermatitis (eczema)
- asthma
- allergic rhinitis (hayfever)
these often occur together due to a heightened immune system to allergens (IgE)
What causes atopic dermatitis?
a genetic predisposition to heightened sensitivity to allergens
weakened skin barrier can be aggravated by environmental factors and irritants such as:
- soaps
- detergents
- cold weather
- frequent harsh washing
- air-borne allergens (pets, pollen)
- food allergies
What does eczema look like in clinic?
there are poorly defined areas of dry erythematous skin
it is a fluctuating illness that gets better until a trigger causes it to flare up again
skin prone to flare ups may be thickened/lichenified, itchy and scaly
How is the distribution of eczema different in infants/toddlers and older children?
Infants/toddlers:
- often widespread and affecting the cheeks
- found on extensor surfaces (wrists, elbows, ankles, knees)
Older children:
- still widespread
- found on the flexor surfaces (behind the elbows and knees)
the eczema is usually cleared by adulthood
How does acute eczema present?
- weeping & crusting of red papules
- swelling
- scaling
- may be blistering
How does chronic eczema present compared to acute eczema?
- it is less vesicular and exudative
- more scales
- pigmentation & lichenification (thick skin with horizontal lines across it)
- fissures may occur
What is the initial treatment for atopic eczema?
Removing any triggers
e.g. wearing gloves, avoiding soaps, using non-biological washing powder, hoovering every day
After removing triggers, what is then done to treat eczema?
all children are told not to use soap and are given soap substitutes
then emollients (ointments or creams)
What type of emollients are recommended for use in children?
How often should they be used?
ointments - these are greasier substances like Vaseline
they keep the moisture in and provide a barrier to the skin
creams have a higher water content but also contain preservatives that can be irritant
they should be applied at least 4 times a day
What is the next step up in eczema treatment after emollients?
topical steroids
there are 4 levels of potency (low, moderate, potent, superpotent)
treatment should be started at low potency and escalated if necessary
What is the next step up in eczema treatment following topical steroids?
calcineurin inhibitors (such as tacrolimus) that reduces the imune reaction in the skin
other treatments include:
- bandaging with dressings
- antibiotics in secondary infection
- antihistamines
- phototherapy
- oral steroids (usually used during a flare up)
What is shown in these images?
irritant contact dermatitis
this typically occurs between finger webs of the hands and at the corners of the mouth
What causes irritant contact dermatitis?
What is it often linked to?
it is due to superficial damage to the skin surface
it is often linked to occupation e.g. irritant contact dermatitis of the hands due to irritants such as soap
Where is irritant contact dermatitis commonly found in children and why?
it is common around the mouths of children due to excessive licking or dribble (saliva is alkaline)
What causes irritant contact dermatitis?
it is due to damage of the skin surface by a substance or material
this allows deeper penetration of the irritant
the extent depends on the irritant and amount/length/frequency of irritant exposure
What are the risk factors for irritant contact dermatitis?
previously damaged skin
What are common irritants for irritant contact dermatitis?
- soaps
- detergents
- adhesives and friction caused by materials
What are the clinical features of irritant contact dermatitis?
- usually only present within the area of contact with the irritant
- red itchy patch that can be well demarcated and dry
- may be swelling and blistering with severe reactions to strong irritants
What are the treatment options for irritant contact dermatitis?
avoidance of the irritant - if the irritant is not removed then it will not improve
emollients & topical steroids can be used to help it heal
it will not get better unless the irritant is removed and sometimes this involves a change of occupation
How is allergic contact dermatitis different from irritant contact dermatitis?
Irritant contact dermatitis is something that most of us would get if we were exposed to the irritant
Allergic contact dermatitis occurs when an individual patient has an allergy to something that most of us don’t have
What causes allergic contact dermatitis?
it is due to a substance or material in contact with the skin causing an allergic reaction
Who is allergic contact dermatitis more common in and why?
more common in women
this is often due to an allergy to nickel present in jewellery
What is it important to ask about in the history for allergic contact dermatitis?
it is often linked to substances used in the place of work
What type of reaction occurs in allergic contact dermatitis?
a type 4 delayed hypersensitivity reaction
the allergen must usually have contact with the skin
How long does an allergic contact dermatitis reaction take to appear?
the reaction may take 48-72 hours to appear after exposure to the allergen
What are common allergens that can trigger allergic contact dermatitis?
- nickel
- perfumed substances
- hair dye (paraphenylene diamine)
- plasters (rosin)
- plants
What are the clinical features of allergic contact dermatitis?
How can clinical diagnosis be confirmed?
- it may resolve on its own as long as the allergen is removed
- it only usually affects the area which had direct contact with the allergen but may spread
- it is often red and itchy, but can become swollen and develop blisters and fissures
- it is confirmed by patch test
What are the treatments for allergic contact dermatitis?
- identify the allergen and take avoidant measures
- emollients
- topical steroids
What is shown in these photos?
seborrhoeic dermatitis
this tends to look more scaly than other types of dermatitis
Where does seborrhoeic dermatitis occur?
Who is usually affected?
it mainly occurs on the face and scalp
dandruff is a mild form
it is more common in young adults, the elderly and males
What is another name for seborrhoeic dermatitis in infants?
infantile seborrhoeic dermatitis is also known as Cradle cap
What is the cause of seborrhoeic dermatitis?
it is caused by an overgrowth of the yeast Malassezia
What are the risk factors for seborrhoeic dermatitis?
- oily skin
- family history
- psoriasis
- family history of psoriasis
- immunosuppression
What does seborrhoeic dermatitis look like in infants and adults?
Infants:
- pink, greasy, flaky patches
- mostly on the scalp but can spread to the armpit or groin
Adults:
- salmon-pink patches, with scales & plaques
- mostly on the scalp, hair-line and facial creases
- can also affect the armpits, under the breasts and groin
What are the clinical features of seborrhoeic dermatitis?
- salmon pink patches with scales and plaques
- not itchy
- flares worse in the winter and improve with sun exposure in the summer
What are the treatments for seborrhoeic dermatitis?
- keratolytics (containing salicyclic acid) to remove the scale
- topical antifungals (to treat Malassezia) - e.g. ketoconazole
- topical corticosteroids (to treat inflammation)
- topical calcineurin inhibitors (to treat inflammation)
- medicated shampoo
What is an alternative name for stasis dermatitis?
Who does it usually affect?
venous eczema
it often affects the lower legs of elderly patients
Why does stasis dermatitis tend to affect the lower legs of elderly patients?
this is the greatest extremity and the elderly have the greatest risk factors for things that would affect their venous return
What are the causes of stasis dermatitis?
venous insufficiency
venous insufficiency results in fluid pooling in the tissues of the leg, activating an immune response and leading to inflammation
What are the risk factors for stasis dermatitis?
- history of DVTs
- cellulitis
- chronic leg swelling
- varicose veins
- venous leg ulcers
What are the clinical features of stasis dermatitis?
- patches/plaques that can be itchy, red and blistered or dry & scaly
- haemosiderin deposition causes a brown discolouration
- atrophie blanche
- lipodermatosclerosis - skin thickening may result
- “upside down champagne bottle” lower leg shape
What is atrophie blanche?
white patches of thin and scarred skin
What is one of the largest risks with stasis dermatitis?
secondary infection can occur leading to cellulitis
this is usually caused by Strep. pyogenes
What is the main treatment for stasis dermatitis?
helping the venous return
this is done by ensuring nothing is obstructing venous return (e.g. deal with DVT / pelvic obstruction)
to reduce leg swelling:
- regularly move the legs (e.g. walking)
- elevate the legs when seated and overnight
- bandaging
- compression stockings
What are further treatments for stasis dermatitis?
- antibiotics for secondary infection
- topical steroids
- emollients or moisturisers
What must be checked before giving a patient with stasis dermatitis compression stockings?
check the lower limbs for arterial disease
if there is poor arterial supply, limbs should not be compressed as this could lead to an ischaemic lower limb
this is achieved by performing ankle brachial pressure index (ABPI)
What is shown in these images?
asteatotic dermatitis
Who is usually affected by asteatotic dermatitis and what brings it on?
- due to dry skin
- commonly occurs on the lower legs
- often due to excess washing
- commonly occurs in the elderly
What is the “typical clinical picture” of a patient presenting with asteatotic dermatitis?
an elderly person who has recently gone into hospital or a care home, where excess washing of the legs and dry skin, exacerbated by air conditioning or central heating, results in inflammation and dermatitis
What causes asteatotic dermatitis?
- it has genetic & environmental causes
- the skin barrier is compromised, allowing excess water loss from the stratum corneum
- can be caused by and exacerbated by low humidity conditions and excess washing
What are the clinical features of asteatotic dermatitis?
- crazy-paving appearance with white patches and red lines
What are the treatments for asteatotic dermatitis?
- remove factors that may have excessively dried the skin e.g. reduce bathing frequency, replace soaps, reduce ambient temperatures
- emollients and moisturisers
- mild topical steroid
