Atopic Eczema Flashcards
What is eczema and dermatitis?
- Terms often used to describe the same condition
- Non infectious, non contagious inflammation of the skin
- characterized by
1. certain clinical - erythema, scales & vesicles)
2. and histopathological changes - spongiosis
What are the different phases of eczema?
- ACUTE:
- redness swelling, papules blisters oozing, crusts - SUBACUTE:
- still red, drier, scalier, pigment changes - CHRONIC:
- lichenification, excoriations scaling, cracks
Note: sometimes all phases are present at the same time
What is erythroderma?
Eczema affects the whole body
Classification of eczema?
- endogenous - atopic
- exogenic - conrtact
Endogenous eczema?
- Seborrhoic
- Discoid - Nummular
- Dyshidrotic
- Asteatotic
- Ichtyosis
Exogenic eczema?
- CONTACT
* Toxic irritant
* Allergic
* Photosensitive
* Vaseline dermatitis - Lichen simplex chronicus
Taking a history of eczema?
- Elicit the nature, course, time of the eczema
- Enquire: atopic symptoms, general medical
conditions, travelling, profession, operation - Identify any factor in social or family history that
may be relevant – e.g.psoriasis, eczema - Record recent drugs and medications,
including topical agents, herbals. - Ask about use of cosmetics, sunexposure
Examining the skin inneczema?
- good light or use hand lens
- Gently palpate lesions to assess
texture, consistency - Observe distribution, individual lesion:
* morphology & configuration
* Localised, widespread, linear, symmetrical, peripheral-central,
flexures - extensors, sunexposed areas, groin, axilla, colour ?
* Nails, hair, mucous membranes, lymph nodes
What is atopic dermatitis?
distinctive pruritic eczematous condition of the skin
* Acute, subacute or chronic
* inflammation of dermis and epidermis
* Very heterogenous
* Pruritus, dry skin
* Symtoms may change often and fast
* May have long periods of remissions
* Always itchy = „the itch that rashes
Epidemiology of atopic dermatitis?
- genetically determined
- Often together with personal or family history
of hay fever, asthma, rhinitis, AD - Starts mostly in early childhood, 10-25% of
infants, 1-3 % of adults - Common disease in people under 25
- Underlies 80% of occupational dermatoses
- Often misdiagnosed, misunderstood and infeffectively treated
Etiology of atopic dermatitis?
Increasingly prevalent and common in industralized countries
- Theory suggests that our overall sterile modern lifestyle
- lack of exposure to parasites,
infections and bacteria creates an imbalance and immaturity for the immune system predisposing us to atopic disorders
Reduced risk for developing atopic dermatitis?
- High exposure of Endotoxins on farms
- Early attendance of Kindergardens
- Dog in the household at birth time
Higher risk for developing atopic dermatitis?
frequently use antibiotics
Features of atopic dermatitis?
- Usually recurrent exacerbations
- Duration of lesions: untreated = month to years
- Itch is the most important clinical symptom, Disturbing
quality and individual way of life in children and adults - Individual therapy and education
What is the atopic march?
the natural history of allergic diseases as they develop over the course of infancy and childhood
- food allergy > atopic eczema > allergic rhinitis > allergic asthma
What is the role of the epidermal barrier?
Tight junctions, desmosomes and adherens junctions form adhesions between the cells of the epidermis to help create a physical, permeability barrier.
Pathophysiology of acropic eczema?
Impairment of the physiology of the skin
1. Reduced activity of sebaceous glands
2. Reduced barrier function of skin
Epidermal barrier dysfunction and atopic dermatitis?
- Genetic mutations for Filaggrin (protein important for composition of the lipids of the skin)
- Genetic mutations for important Proteases have been described
- Secondary proteases: produced by inflammatory cells
- Exogen proteases:
* Dust mites
* Staphylococci
Influencing factors for developing atopic dermatitis?
- detergents
- allergens
- staph aureus
- Malassezia sp.
- hormones
- neuropeptides
Diagnosis?
clinical findings
Skin symptoms?
- ITCHING - Eczema is the itch that rashes“
- Vicious circle of itch:
> Itch – scratch – rash - itch - DRY SKIN:
> Lichenification of the skin
Consequences of the itch?
- Causes rubbing, scratching, flare up
- Interferes sleep, rest, concentration, growth
and learning. - May dominate waking hours, torture,
embarrassing - an individual want to itch, continuing the
itch-scratch cycle - DON`T UNDERESTIMATE THE
PSYCHOLOGICAL IMPACT OF PRURITUS IN A
YOUNG PERSON!! And their family
Major criteria for atopidc dermatitis?
- Pruritus
- Morphology and distribution
- Flexural lichenification (adults)
- Facial and extensor involvement (infancy)
- Chronic relapsing course
- Pos. Family - or own history of Atopy
- requiring 3 of 4 basic features +
Minor criteria for atopic dermatitis?
3 or more features
1. Xerosis (dryness)
2. Ichthyosis/palmar hyperlinearity/keratosis pilaris
3. Immediate (type I) skin test reactivity
4. Elevated serum IgE
5. Earyl age of onset
6. Tendency towards cutaneous infections (S.aureus and
Herpes simplex ) – “Defensin-Defect“
7. Tendency towards nonspeciific hand or foot dermatitis
8. Nipple eczema
9. Cheilitis
10. Recurrent conjunctivitis
11. Dennie-Morgan infraorbital fold
Distribution of lesions in baby/infancy?
- Face, wrists,
- Extensor sites
Distribution of lesions in childhod?
Antecubital, popliteal fossae, neck, abdomen
Distribution of lesions in adults?
- flexures, front and sides of neck
- eyelids, forehead, face, wrists
- dorsa of feet and hands, often generalized
Describe acute skin lesions?
- Poorly defined erythematous
patches possibly scaling - Skin appears puffy
- Moist, crusted erosions
Describe chronic skin lesions?
- Lichenification
- Follicular eczema
- involvement of all hair follicles: discrete follicular papules - Fissures - painful
What is pityriasis alba?
Postinflammatory Residual Hypo- and
hyperpigmentation leads to Medical consultation
Ddx for pityriasis alba?
- Vitiligo
- Leprosy
- Seborrhoic dermatitis
- Discoid Lupus eryth
- Contact dermatitis
- Psoriasis
Ddx for atopid dermatitis?
- Other forms of Eczema
- Psoriasis
- Pellagra
- Infections and infestations
* Scabies
* HIV-associated Dermatoses
* Dermatophytoses - Malignancies/adults
* Mycosis fungoides, Sezary Syndrome, KS
Complications of AD?
Bacterial Infections
* Staphylococcal
* Streptococcal
Viral infections
* Mollusca contagiosa
* herpetic infection
Microbial flora of AD?
Staphylococcus aureus
found in
* Lesional skin: >90%
* Uninvolved: >70%
* Nasal Passage: 79%
Describe herpetic infection in AD?
- Secondary infection to atopic dermatitis
- Eczema herpeticatum – varicelliform eruption
- Potentially life threatening
AD exacerbation factors?
SKIN DEHYDRATATION/IRRITATION
* Frequent bathing and hand washing
* Direct wool contact (clothing, blankets)
* INFECTIONS
* Staphylococcal, streptococcal, fungal, viral
infections
* EMOTIONAL STRESS
* ALLERGIES
* Contact allergens, Food, Inhalants
How does stress get into the skin?
Psychological stressors contribute to
the severity of chronic inflammatory diseases such as psoriasis or atopic dermatitis
- Dysregulation of the Hypothalamic–pituary-adrenal-Axis activity
What is the atopy patch test?
Epicutaneous patch test with allergens known to elicit IgE-mediated
reactions, for the provocation of eczematous skin lesions due to these
allergens
What is the skin prick test?
- Method of choice to detect IgE-mediated
immediate type hypersensitivities
– should always be used prior to
all other in-vivo/in-vitro tests.
Allergens in AD?
Grass/ Tree pollens - proteins
* most common cause of hayfever
* wind pollinated: not colourful flowers
* House dust mites, - mite faeces
* Cockroaches - house dust
* Animal products: Cat, Dog, Cow, Horse, Birds
* Food
* Microfunghi- Mould spores
Prick test procedure?
REGION:
* VOLAR FOREARM
» CLEAN SKIN –
» APPLY 1 DROP OF ALLERGEN SOLUTION
(50% Glycerolallergen extract)
» “PRICK” THE SKIN THROUGH THE DROPwith a lifting motion
» REMOVE DROP NOT BEFORE 3 MIN.
» READING AFTER 20 MINUTES
What does a positive prick test mean?
ALWAYS INTERPRETE IN CONTEXT WITH HISTORY!
* HISTORY positive
» PROOF FOR ALLERGY
* HISTORY negative
» SENSITIZATION
* HISTORY QUESTIONABLE/UNCLEAR
» ALLERGY/ SENSITIZATION POSSIBLE?
Use of the prick test?
CAN BE USED TO TEST NATIVE
ALLERGENS
* FOOD
* DRUGS
* USE DILUTIONS (start with 1: 1000 of
therapeutic dilution) !!!!!
* “everything”
Management of AD?
Avoid irritants !!!!!!!!!!
soap, mineral oil, woolen clothes, heat, sweat, dry air
Keep fingernails short
Use Emollients: Lubrication of the skin
Aqueous cream or emulsifying ointment
