Eczema - Lecture notes Year 4 Dermatology PDF

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Summary

Eczema Overview...

Description

Eczema Superficial skin inflammation with vesicles, redness, oedema, oozing, scaling and usually pruritus. Most common type is atopic eczema.

Atopic Eczema (also referred to as atopic dermatitis):

Key Points: - Typically an episodic flare of disease (exacerbations) which occur as frequently as 2-3 times/month. - Atopic is used to describe a group of conditions (eczema, asthma, hay fever and food allergy) which are linked to an increased activity of the allergy component of the immune system. - Family history of atopy is linked to its development. - Normally starts in infancy and is episodic in nature. Aetiology: ● There is a significant hereditary predisposition - thought to cause an abnormality in the epithelial barrier function allowing antigenic and irritant cells to come into contact with immune cells. ● Cause is not really known. Clinical Features: ● The rash: ○ Itchy - this is a highly sensitive symptom, no itching means it is unlikely to be atopic eczema. ○ Erythematous ○ Scaly due to thickening of the epidermis ○ May initially present on the hands - in adults. ○ In front of the elbows and behind the neck and knees (flexures of the body) (in children) ○ In infants it is likely to present on the face, scalp, and the extensor surfaces of the limbs. ● Scratching produces excoriations and repeated rubbing causes skin thickening (lichenification) with exaggerated skin marks. ● Open skin can become secondarily infected by S. aureus (weeping and crusty impetigo-like lesions) or herpes simplex virus causing multiple small blisters or punched out lesions (eczema herpeticum) which can be fatal. Acute flares will see the development of redness and vesicles, scaling and crusting and lichenification from excoriation. Diagnostic Criteria (according to NICE) - Itchy skin condition PLUS three of the following:

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Visible flexural eczema involving the skin creases, such as the bends of the elbows. - Or cheeks/extensor surfaces in 18months or younger. History of flexural eczema History of dry skin in last 12 months History of other atopic disease (or in a first degree relative) Onset of signs and symptoms before the age of 2

Severity: - Clear (no evidence of eczema) - Mild (areas of dry skin and infrequent itching +/- small areas of redness) - Moderate (if there are areas of dry skin, frequent itching and redness) - Severe (if there are widespread areas of dry skin, incessant itching and redness) - Infected (signs of secondary bacterial infection - such as weeping, pustules) Remember to ask about impact on QoL Management: https://bnf.nice.org.uk/treatment-summary/eczema.html - good overview General Principles:

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Advice on recognising flares Advice on eczema herpeticum which is an emergency (see below) Advice on spotting superinfection

Mild:

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Emollients (see below) Mild topical corticosteroid - hydrocortisone 1% for areas of red skin - See below for examples and strengths Refer if uncontrolled/refractory

Moderate:

Severe:

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Generous emollient prescribing For inflamed skin consider a moderately potent steroid such as betamethasone valerate 0.025%) - Continue for 48hrs post-flare - For delicate areas such as face and flexures consider milder steroid (hydrocortisone 1%) - For itch relief, prescribe a non-sedating antihistamine (cetirizine/loratadine or fexofenadine) Note the need to review steroid use at 3-6 months and antihistamines at 3 months. With steroid use aim for a max of 3 months. - Refer for a routine dermatology appointment -

Generous amounts of emollients Potent steroid use for severe If itching is affecting sleep then consider a short course of sedative antihistamine (chlorphenamine) If extensive eczema is causing distress then consider a short course of oral corticosteroid - 30mg prednisolone taken in the morning for 1 week should be sufficient.

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Infected:

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Note that topical calcineurin inhibitors are a second line option - Tacrolimus - Pimecrolimus

Rule out eczema herpeticum (emergency) see below. Swab the skin and send for MCS Prescribe flucloxacillin - Erythromycin if penicillin allergic - If cannot tolerate erythromycin due to nausea and cramps then clarithromycin Consider a topical antibiotic

For advice on prescribing corticosteroids and emollients see the link below as it explains it all including finger-tip units. https://cks.nice.org.uk/topics/eczema-atopic/prescribing-information/topicalcorticosteroids/

Eczema Herpeticum: Medical Emergency Key Points: - A recognised complication of atopic eczema. - It is caused by HSV1 or 2 infection

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Will likely have a fever and signs of infection

Risk Factors: - Marked early-onset, severe atopic eczema. - Marked elevations in IgE and elevated allergen specific IgE levels - Peripheral eosinophilia

Presentation: - Rapidly progressing PAINFUL rash - Grouped vesicles with punched-out erosions. - Disseminated HSV infection presents with widespread lesions that may coalesce into a large group. - Bleeding areas that can extend over the entire body, occasionally complicated by secondary infection with staph/strep. - Fever, lymphadenopathy and malaise are all common Management: - Medical emergency - especially in children under 2. - It can have serious sequelae such as eye or meningeal involvement resulting in scarring. - Admit children for IV acyclovir

Pompholyx (sometimes called dyshidrotic eczema): Dyshidrosis is the process of formation of fluid-filled blisters, which typically occur on the soles of the feet, palms of the hands and sides of fingers.

Key points: - Type of eczema which affects both the hands (cheiropompholyx) and the feet (pedopompholyx). - It may be precipitated by humidity and high temperatures. Features: - Small blisters on the palms and soles - Once they burst they can become dry and crack - Pruritus - Intensely itchy - Sometimes associated with a burning sensation Management: - Cool compresses - Emollients - Topical steroids

Discoid Eczema (nummular dermatitis):

Key points: - Cause is unknown - sometimes it is associated with staphylococcus infection. Presentation: - Common - very itchy - Scattered, well defined, coin shaped and coin sized plaques of eczema. - Typically affects the limbs, particularly the legs Clinical Subtypes: - Exudative - oozy papules, blisters and plaques - Dry - subacute or chronic erythematous dry plaques Investigations: - Swabs will reveal bacterial superinfection (staphylococcus aureus) Management: - Protect the skin from injury as it is often commenced following a break in the skin. - Emollients - Avoid allergens - maybe even go allergy clinic for patch testing - Topical steroids - Antibiotics and oral antihistamines

Venous Eczema:

Key points: - Common form of venous eczema that affects one or both lower legs in association with venous insufficiency. Often called gravitational dermatitis. - Caused by accumulation of fluid in the tissues which activates an innate immune response. RFs: -

Hx of DVT Hx of cellulitis Chronic swelling of the leg associated with venous insufficiency, varicose veins or venous ulceration.

Clinical Features: - Itchy red, blistered and crusted plaques. - Orange-brown macular pigmentation due to hemosiderin deposition - Atrophie blanche (white irregular scars surrounded by red spots) - Lipodermatosclerosis (narrowing at the ankles and induration which has a ‘champagne bottle’ appearance). Management: - Reduce swelling by not standing for long periods, walking, elevating feet and bandaging (DN) - PO flucloxacillin for superinfection. - Topical steroid cream daily to the patches until they are flatter, then change to a milder cream (hydrocortisone) until the patches have resolved (maintenance treatment)....