Dermatitis and Eczema Flashcards
What are the exogenous classifications of dermatitis?
*caused by external agents
Irritant contact dermatitis
Allergic contact dermatitis
What are the endogenous classifications of dermatitis?
*no external cause, presumed to be due to internal pre-disposition
Atopic dermatitis
Seborrhoeic
Discoid
Asteatotic
Pompolyx/dyshidrotic
Outline the characteristics of irritant contact dermatitis
most common
Due to freq exposure to chemicals or substances which damage skin (soap, dripple, spit, detergents, water)
Chronic = very dry, thickened, cracking skin
Discuss napkin dermatitis
Common in infants/toddlers
Grow out of it when nappies stopped
Can be more atopic than irritant
complicated by secondary candida infections
Discuss the characteristics of allergic contract dermatitis
True allergy, patch test confirms allergy
Occurs in unusual patterns related to contact with allergen, can extend beyond contact area
e.g. plasters, watch band, plant contact, rubber gloves, nickel earrings, jean stud
What is asteatotic dermatitis?
common in elderly, typically lower legs
Characterised by very dry, flaking skin which splits = cracked dermatitis, carving paving appearance
Worse in winter (low humidity), soaps, household heading, other drying agents
When is atopic dermatitis more common?
Infancy/childhood
Genetic predisposition (atopy)
Worse in winter, relapsing chronic condition
Outline the characteristics of atopic dermatitis/eczema
Red scaly eruption which can be weeping and encrusted in acute phase = flextures, cheeks - young children
Chronic scratching (intense itch) and rubbing
Prone to infections = itchy = dry, split skin
Cycle = infection —> worsen eczema –> more treatment resistant (abx required)
Outline the characteristics of discoid dermatitis
Round, disc-like lesions, clearly demarcated, intensely itchy, erythematous, scaling lesions
Confused with tinea/ring worm
Tend to be acute, weeping, develop secondary infection
Anywhere on trunk and limbs, not common on head and neck
Outline the characteristics of dyshidrotic/pompholyx dermatitis
Small vesicles (blisters w/ clear fluid), intensely itchy, burning feeling, sore
Affects hands and sometimes feet
What is the difference between dyshidrotic and pompholyx dermatitis?
Pompholyx is a severe form = peeling, flaky skin, vesicles, similar to fungal infections –> stress
What are some non-pharm treatments for dermatitis?
Avoid precipitating factors
Avoid scratching
Bath every 2nd day
Pat skin dry, dont rub
Keep skin cool
occlusions or wet dressings
What are some OTC/S3 treatments of dermatitis?
Soap substitutes
Emollients/moisturisers
Anti-histamines
Tar/Ichtammol
Topical corticosteroids (hydrocortisone, clobetasone, mometasone furoate)
Probiotics
Colloidal oatmeal
Discuss the use of tar preparations in dermatitis treatment
Exact MOA unknown –> reduce epidermal thickness, antipruritic/antiseptic
Compliance = challenge (odour, stains)
Photosensitivity
Generally highlight the effects of topical corticosteroids in treatment of dermatitis
Relieve redness, itching, inflammation
Choose potency appropriate to site and severity
Use for short time necessary to control skin disorder
Discuss the use of hydrocortisone in treatment of dermatitis
Mildly potent = treat flare ups
Available combined with antifungals or local anaesthetics
How often should topical corticosteroids be applied for dermatitis?
Apply to affected area/s up to tds
Most applied bd except clobetesol, methylprednisolone, and mometasone (od)
Discuss the use of clobetasone in dermatitis treatment (how often apply)
More potent than hydrocortisone
Apply bd to affected area/s
How often should mometasone furoate be applied to treat dermatitis?
Od to affected area/s
Which topical corticosteroids dont have dosing freq of “bd”?
clobetasol
mometasone
methylprednisolone
All above applied od
What are finger tip units? (FTU)
Used to measure the application of topical corticosteroids
1FTU = cover twice the size of flat adult hand (fingers together)
Man FTU = 0.5g
Female FTU =0.4g
How many finger tip units cover the neck and face of an adult?
2.5 FTU
How many finger tip units cover the chest and abdomen (combined) of an adult?
7 FTU
How many finger tip units cover a single arm of an adult?
3 FTU
How many finger tip units cover the back and buttocks (combined) of an adult?
7 FTU
How many finger tip units cover the hand of an adult?
1 FTU
How many finger tip units cover the leg (single) of an adult?
6 FTU
What are some other prescription treatments for atopic dermatitis?
Calcineurin inhibitors = inhibitor of inflam cytokines –> block T cell activation, prevent inflam mediators
- 2nd line if topical SAIDs don't work, >3 months old, req sun protection
Crisaborole = PDE-4 inhibitor –> reduces secretion of cytokines
- mild - moderate atopic dermatitis in patient >2 yrs and above
How often should Calcineurin inhibitors and Crisaborole be applied to treat dermatitis/eczema?
Crisaborole = used bd for up to 28 days/course
Calcineurin inhibitor = bd. 3-6 weeks depending on age
What immunosuppressants are used for atopic dermatitis?
Methotrexate
Ciclosporin
Azathioprine
mycophenolate
prednisolone
What biological agents are used to treat Atopic dermatitis? (-mab, -tinibs)
Dupilumab = immune cases, sub-cut
Upadacitinib = JAK inhibitor –> suppress immune system (moderate, severe atopic dermatitis)
Baricitinib = JAK inhibitor, moderate or severe atopic dermatitis
Outline some referral points for dermatitis
Secondary bacterial infection present/exists
Serious underlying disease (diabetes)
Large/extensive area/s, moist and/or bleeding
Correct differential diagnosis = patch test, if eczema treatment recommended (esp in presence of topical steroid)
What are some precipitating factors for dermatitis?
Allergens = house dust mites, grass, animal dander
Soaps, detergents, perfumes
Shampoos = avoid sodium lauryl sulfate and/or washing/rinsing hair over a basin
Sweating can increase itch
What are some lifestyle changes for dermatitis?
Manage and control itch
Avoid precipitating factors
Maintain skin integrity
What are some differential diagnoses for dermatitis/eczema?
Tinea - active outer, red scaling edge and clear centre. Tines not typically itchy
Psoriasis - thickened plaques w/ diffuse silver scale on extensors of knees and elbows. Both itchy and affect palms and soles
- dermatitis is typically on opposite side, will be on flextures
