SSS Week 7

Dermatitis vs eczema

terms are used interchangeably but … technically eczema is a type of dermatitis.

Dermatitis refers to any cause of skin inflammation affecting the epidermis

Eczema - oedema within the epidermis (called spongiosis)

Acute vs chronic dermatitis

Acute - red, wet, oozing, even blistering

Chronic - skin thickened, dry, scaly, and fissured (lichenification - secondary lesion)

Subacute - stage between acute and chronic so will show features of both

Seborrhoeic dermatitis

(endogenous)

• red itchy patches (which become scaly or crusted)

• caused by combination of endogenous factors and overgrowth of malassezia furfur yeast

• dermatitis may be aggravated by a combination of endogenous factors - illness, stress, fatigue, change of season, and reduced general health (eg. especially infection with HIV)

1. Infantile seborrhoeic dermatitis

   • characteristic cradle cap ‘greasy’

   • erythematous but non-itchy rash, well defined and covered in greasy scale… (sebaceous glands release a greasy substance that makes old skin cells attach to scalp as they try to dry and fall off)

   • the rash may spread to affect armpit and groin folds (via flexures)

   • possibly due to overactive sebaceous glands in skin of newborn babies due to maternal hormones still in baby’s circulation

   • super-infection with staph and candida albicans is common resulting in weeping and crusting

treatment: for

mild/localised - use gentle emollient or repeated shampooing, remove scales with a soft toothbruhs or comb

extensive/resistent - treat with low-potency topical steroid or antifungal for 1-2 weeks…. topical steroid preferred if significant inflammation

2. Adult seborrheic dermatitis

   • usually appears at any age after puberty

   • exacerbated by emotional and physical stress

clinical features: erythema and fine, greasy scale on cheeks, nose and nasolabial folds

scale and itching of scalp and eyebrows

well defined but non scaly, erythema of axillae, groin, scrotum and perianal skin

management:

scalp:

• anti-dandruff shampoos containing selenium sulphide, ketoconazole, miconazole or zinc pyrithione (which all control malassezia)

• tar containing shampoos are also helpful and combination of a tar and antifungal shampoo gives better control than either alone

non scalp areas:

• topical steroids first and consider adding topical antifungal agent for malassezia

• weak tar creams such as LPC 2% cream may assist (you used this! for something else tho)

Atopic dermatitis (+aetiological factors* (5), clin features (5), distribution, treatment 9) + pityriasis alba

(endogenous)

• most common form of dermatitis

• atopic eczema also associated with asthma, allergic rhinitis (hayfever), food allergies

aetiological factors

1. family history

2. immune dysregulation - increased IgE due to Th2 immune dysregulation

3. abnormal epidermal barrier - deficiency of fillaggrin (an epidermal protein) which causes impaired skin barrier which holds water poorly and is more susceptible to irritants and allergens

4. susceptibility to infection - epidermis is deficient in peptides known as defensins

5. environmental irritants - bc of the impaired epidermal barrier eg. soap, sand, woollen, synthetic fabrics and dust

clin features

1. a patchy erythematous, poorly defined rash

2. xeroderma - dryness of skin

3. excoriation (de to scratching and itching)

4. lichenification (prurigo may develop)

5. in bacterial infections crusting and weeping

Distribution

infants

• cheeks are often first place

• may have widely distributed small patches of eczema

• napkin area is frequently spared due to mositure retention of nappies

• tends to be vesicular and weeping

• in babies of non-caucasian descent, a micropapular variant is common (instead of vesicular) and temporary hypo/hyperpigmentation may occur

toddlers and pre-schoolers

• as children begin to mvoe around, eczema becomes more localised and lichenified

• flexor aspects of joints (wrists, elbows, ankles, and knees +maybe genitals)

• some individuals have reverse presentation where it affects the extensors

• some develop discoid pattern

adults

• become quite localised involving hands, eyelids, nipples, genital area, lips or face

• in severe: it may involve entire skin (erythroderma)

TREATMENT

1. explanation fo chronicity and overall good prognosis (requires long term management not just reactive care, also need to treat flareups)

2. modification of lifestyle to avoid exacerbating factors

3. use of moisturisers and bath additives (use of emollients and bath oils)

4. investigation and treatment of infection (MCS if flare ups, antibiotics), for recurrent or chronic, add a very dilute chlorine bleach to water

5. discussion, possible investigation and treatment of allergy (allergy testing)

6. use of topical anti-inflammatory agents (MAINSTAY- TOPICAL CORICOSTEROIDS)

7. understanding role of anti-histamines (minimal use as not much benefit)

8. use of wet dressings

9. understanding psychological issues

other options

Pityriasis alba

• low-grade type of atopic dermatitis mainly seen in children

• mild scattered areas of facial eczema complicated by depigmentation on face

• several round or oval slightly scaly pink patches appear, leaving pale marks when redness faded

• regresses spontaneously

• more apparent in summer, especially in dark-skinned children

management: weak topical corticosteroid, emollient and soap avoidance

once dermatitis is controlled, sun exposure will return the pigment

Discoid dermatitis (two forms)

(endogenous)

• affects middle age and elderly

• OFTEN with a previous history of atopic dermatitis

• pink, red, brown and well defined, dry cracked surface and can have blistered or crusty surface

TWO FORMS

• exudative (wet) nummular dermatitis: oozy papules, blisters and plaques

• dry nummular dermatitis: red scaly, very itchy, discrete, round or oval plaques with well defined edge

• may be symmetrical

• lichenification can occur rapidly due to intense scratching

• affects any part of body particularly lower leg

treatment: similar to atopic dermatitis

• moderately potent topical steroids are usually requried

• lichenified lesions may require very potent topical steroids or intralesional steroids

• wet wraps

• antibiotics if bacterial infection

Stasis dermatitis (+complications (8) and management)

• occurs on lower legs due to chronic venous hypertension

• mainly in elderly women

• look for venules, phlebactasia and brown haemosiderin deposition around ankles (early signs)

characteristic dryness, scale and brown hyperpigmentation (due to diapedesis of red blood cells from peripheral circulation into dermis, eczema and ulceration can subsequently develop

• usually associated varicose veins, woody oedema (due to lipodermatosclerosis)

• allergic contact dermatitis may coexist (eg. bandages or leggings for chronic venous hypertension may be an irritant/allergen)

Management

• dryness is managed by avoidance of soap, using a soap substitute and application of a greasy moisturiser at least twice a day

• inflammation treated by moderate topical corticosteroid

• acute attacks are settled by short bursts of potent topical corticosteroids, wet dressings and antibiotics if an infection (like discoid and atopic management)

• In order to treat and prevent you need to treat the cause of the stasis dermatitis by attention to the underlying venous insufficiency. This involves compression bandaging or stockings and elevation of the foot of the bed at night

Pompholyx (dyshidrotic) dermatitis

(endogenous)

• a vesicular or bullous dermatitis

• affects palms, sides of fingers and soles of feet

• cause: unknown, may be precipitated by stress, sweating and overheating

• acute stage: vesicles deep in skin of palms, fingers, instep or toes, the blisters are often intensely itchy or have a burning feeling, the condition may be mild with only a little peeling or very severe with large blisters and cracks

Management

• Management is the similar as for other dermatitis.

• Potent topical corticosteroids should be used initially with wet dressings and antibiotics if secondary bacterial infection.

• Rest is important and because of the location on the hands this can mean time off work for adults.

• After an acute attack, the skin is vulnerable, and patients need to protect their hands from irritating substances including soap for three months.

• Very severe attacks of bullous Pompholyx may require a 2-to-3-week course of oral prednisone.

Asteatotic Dermatitis

(miscellaneous)

hypothyroidism can contribute to condition

Irritant dermatitis

(exogenous)

Cause

• Strong irritant elicit an acute reaction after brief contact

• Sometimes a weak irritant over many years

• Usually, hands and forearms

• E.g. water, detergents, chemicals, oils o Previous Atopic dermatitis increases the risk

Often on backs of hands, between fingers, Napkin area

• Dry "chapped". Later thickened and fissured

• more likely in Cleaners, catering, hairdressing, engineering, health workers

Investigations - patch testing with irritants is not helpful but with common allergens may be

treatment

• avoidance of irritant

• protective gloves and clothing

• barrier cremes more for prevention

• avoid harsh solvents when cleaning hands

• emollients

• corticosteroids

Allergic contact dermatitis

(exogenous)