Dermatitis/Eczema Flashcards
What are the characteristic features of any dermatitis rash?
ITCHY
Ill-defined
Erythematous
Scaly
What may been in the acute phase of the rash?
Papules, vesicles Erythema Spongiosis (oedema) Ooze Scaling Crusting Excoriations
What may be seen int he chronic phase of the rash?
Lichenification (thickening)
Elevated plaques
Increased scaling
Excoriations
What are the two different types of contact dermatitis?
Irritant
Allergic
Which type of hypersensitivity is contact allergic dermatitis?
Type 4 (delayed)
How do you diagnose contact allergic dermatitis?
Patch testing
Give some examples of causes of contact allergic dermatitis
Nickel, chemicals, plants, topical therapies
What is the process of having patch testing done?
Three appointments in 1 week
- allergens put on back (first appointment)
- allergens taken off back 48 hours later
- reactions checked at 96 hours (third appointment)
How is irritant dermatitis different to allergic?
Non-specific physical irritation rather than specific allergic reaction
(difficult to tell the difference)
Give some examples of causes of irritant dermatitis?
Soap, detergent, cleaning products Nappy rash (urine is irritant)
What is the typical distribution of atopic eczema?
Flexural (from of wrists, back of knees etc)
In infants –> cheeks and extensor surfaces
Which other conditions is atopic eczema associated with?
Asthma
Allergic rhinitis (hay fever)
Other allergies e.g. food
Which chronic changes are seen in atopic eczema?
Lichenification
Excoriation
Secondary infections
Which gene may be involved in eczema?
Filaggrin gene
What is the diagnostic criteria for atopic eczema?
ITCHING + 3 or more of:
- visible flexural rash (cheeks/extensors in infants)
- history of flexural rash
- personal history of atopy (or first degree relative if < 4 years old)
- generally dry skin
- onset before age of 2
What is step 1 in the management of eczema?
Emollients alone
What is step 2 in the management of eczema?
Emollients + mild TCS (topical corticosteroid)
What is step 3 in the management of eczema?
Emollients + moderate TCS
+/- calcineurin inhibitor
What is step 4 in the management of eczema?
Emollients + potent TCS (short term)
+ specialist advice
What practical advice should be given to someone with eczema?
Avoid allergens/irritants
Emollients twice daily, even if eczema is fine
Avoid having sweaty skin
Use emollients in place of soaps in bath/shower
When are ointments better than creams?
For dry, scaly, fissured or lichenified skin
When are creams better than ointments?
For hot, inflamed, urticated skin
What advice should be given for using ointments?
Use a spoon to take out of pot rather than fingers
–> doesn’t contain preservative so easily contaminated
Name a mild TCS?
Hydrocortisone 1%
Name some moderate TCS?
Modrasone, Clobetasone, Butyrate 0.05%
Name some potent TCS?
Elocon, Betamethasone (betnovate), Valerate 0.1%
Name a very potent TCS?
Clobetasol proprionate 0.05%
What are some side effects seen with potent/very potent steroids?
Skin thinning –> striae
Increased skin infections
Telangiectasia + steroid acne (Betnovate)
Systemic absorption –> poor growth, cushingoid features
How much surface are does a fingertip unit of TCS cover?
2 hand areas
How much TCS would be required to cover a whole adult body?
20 - 30g
How much emollient should be prescribed to last 1 week?
250 - 500g
What are calcineurin inhibitors and when are they used?
Potent anti-inflammatory agents without the steroid side effects
Second like topical therapy for severe eczema
Give two examples of calcineurin inhibitors
Tacrolimus 0.1%
Pimecrolimus (face only)
Give some examples of physical therapies used in eczema?
Bangages - impregnated with zinc oxide paste +/- tar, antimicrobials
Wet wrap therapy
What is the role for antihistamines in eczema?
No evidence for efficacy but sedative effects may help children to sleep if this is a problem
–> contraindicated in children < 6 months
What does Staph aureus infected eczema look like?
Golden crust
How should you treat Staph aureus infected eczema?
Fucidin ointment (antibiotic) --> 5-10 days Consider antiseptics
How should eczema herpeticum be treated?
Emergency oral aciclovir
What is a rare complication of eczema herpeticum?
Encephalitis
What is seborrhoeic dermatitis?
pink scaly patches on scalp, eyebrows and nasolabial folds (oily areas)
–> very common (stubborn dandruff)
Which conditions are associated with seborrhoeic dermatitis?
HIV and other immunosuppressive states
What does discoid eczema look like?
Discs of eczema, similar to psoriasis but not as well demarcated
What causes discoid eczema?
Chronic itch, rubbing and scratching
–> atopic eczema, itch from CKD
What is nodular prurigo?
Similar to discoid eczema, consequence of chronic itch
What is pompholyx eczema?
Itchy vesicular eczema on palms and soles
Which eczema is seen only on sun exposed sites?
Photosensitve eczema aka chronic actinic dermatitis
What is stasis eczema?
Aka venous eczema
Seen in lower legs secondary to hydrostatic pressure, oedema and red cell extravasation
–> chronic venous insufficiency, varicose veins, DVT
What does lichen simplex look like and what causes it?
Localised plaque of lichenified, chronic eczema
Response to scratching/rubbing over a long period of time
