Eczema

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Fromfinish :

  • Eczema is an inflammatory dermatosis, erythematous vesicular, CASTROTHEODORICIENNE
  • This is the most common skin diseases
  • The predominant histological lesion is spongiosis mucosal body Malpighian
  • This eczema group has two well-defined entities : allergic eczema and atopic dermatitis Contact (atopic dermatitis)

Study clinique :

  • Eczema acute : the eczema flare evolves 4 stages :

Phase erythematous : erythematous cupboard, edematous, hot, fading from vitropression, edges crumbled

Phase vesicular : after a few hours, vesicles appear on the surface of the erythema, contain a clear serous fluid

Phase from suintement : the vesicles rupture and leak yellowish serous fluid, the closet then covered with yellowish scabs (coagulation of the serum)

Phase from repair (desquamation phase) : the scabs fall appears a pink skin, fripé, strongly desquamative

  • Eczema chronic :

Eczema lichenifie : appearance of a greyish plate, thickened, quadrillée et très CASTROTHEODORICIENNE

Eczema chronic of the palms and of the plants : appearance of a palmoplantar keratoderma

Note : the edges of eczema lesions are usually crumbled, pruritus is constant

Histologie :

Useful for diagnosis in atypical forms

  • At level from l & rsquo; epidermis :

Spongiose : edematous distension of intercellular spaces, making small vesicles

Exocytose : inflammatory cells (lymphocytic +++) from the dermis

  • At the dermis : edema, capillary dilatation and inflammatory infiltrate

Eczema from contact :

  • Definition : major cause of eczema in adults, is an inflammatory dermatosis acquired, due to percutaneous awareness molecules non-tolerated or allergens
  • pathophysiology : is a delayed hypersensitivity reaction cell mediated, in 2 phases :

Phase from sensitization : a few days to several years, exogenous sensitizer is usually a hapten (small substance, non-immunogenic by it- even) which penetrates the skin and is associated with a protein to form a couple "hapten- protein " (allergen) which will be captured by epidermal Langerhans cells and presented to LTs and lymph nodes. These activated LTs proliferate under the action of IL2 and then differentiate into circulating "memory" lymphocytes

Phase from revelation : 24-48h, after a new contact with the allergen, Tm lymphocytes specific for the allergen (re)cutaneous circulation recognize the allergen presented by Langerhans cells, they proliferate and secrete pro-inflammatory cytokines (IL2, TNFα) recruiting mononuclear inflammatory cells responsible for the clinical and histological response of eczema

  • Diagnostic etiological :

Examination : very important element of the etiological, must be sought :

Topography initial : lesions are initially localized to the area of ​​contact with the allergen, they can then diffuse away

circumstances from release : specify the activities that could have led to a contact with a particular allergen 24 hours to a few days before : profession, gardening, applying a cosmetic ...

Chronology : lesion progression over time (vacation, work stoppages)

treatments local used : before and after the onset of dermatitis

Exam clinique : will specify the elementary lesions and changes in 4 stages + pruritus, some locations have an orientation value :

▪ lobule of the ear, wrist and navel -> Awareness Nickel

▪ Face, eyelids or neck -> allergy to cosmetic, nail polish, parfums

▪ Feet : allergy to a constituent shoes (Of chrome add)

Tests cutaneous (patch tests) : These tests reproduce the same lesions as eczema

Technique : on the dorsal skin, outside of an eczema flare and away from a local corticosteroid, the substance to be tested is applied and covered with a non-allergenic support (cellulose pellets). We usually make European standard batteries (25 substances most frequently involved), sometimes specialized batteries oriented

Lecture : is made 48 hours, 15 minutes after removing the test, a second reading is carried out at 72-96h, sometimes 7 days to some allergens (corticosteroids)

Test negative : normal skin

Test positive : reproducing the eczema lesion : (+) -> erythema, papule, (++) -> erythema, papule, vesicle, (+++) -> erythema, papule, nombreuses vésicules confluentes (bubbles)

main causes :

allergens professional : occupations most often involved are :

crafts of building : cement, painting, colle, varnish, carpentry, rubber

Hairdressers : dyes, preservatives and foaming agents, Nickel (instruments)

Profession from health : antiseptic, antibiotics, AINS, neomycin, plaster

cosmetics : parfums, preservatives, excipients, nail polish, deodorants, shampoos, lacquers, balsam of Peru (lipstick, creams)

products clothing : colorants textiles, please, glue shoes, rubber, costume jewelry, accessories (watch, Buckle, buttons jeans) : Nickel

Photoallergens : certain allergens induce contact dermatitis after UV irradiation -> sun-exposed areas (AINS, some plants)

  • Diagnostic differential :

Dermatitis irritation : secondary physical attack or chemical direct (non- immunological), can take the acute or chronic eczema appearance, occurs during the first touch

Dermatitis (or eczema) atopic

Edema of face : erysipelas, Angioedema (Angioedema), zone

Eczema constitutional (Atopic dermatitis) :

  • Definition : is a chronic pruritic inflammatory skin disease, occurring on atopy, common (10-20% children). Atopy describes a specific condition characterized by a genetic predisposition to increased IgE synthesis and allergic diseases (allergic rhinitis, conjunctivitis, asthma, eczema)
  • pathophysiology : multifactorial disease, results from the interaction between :

factors genetic : it is a polygenic complex disease, two types of genes appear to be involved : genes of the epidermal barrier located in the area of ​​the epidermal differentiation complex 1q21 (whose gene filaggrin) and genes that regulate the specific and innate immune system. The concordance of the disease is 80% in monozygotic twins and 30% dizygotic, 50-70% DA patients have a first-degree relative with a DA, of asthma or allergic rhinitis

factors immunological : the delayed hypersensitivity reaction involving T lymphocytes and antigen presenting cells, release of cytokines into the skin by activated lymphocytes -> eczema lesions

Anomalies inborn from the fence epidermal : abnormalities of the horny layer and skin lipid explain skin dryness, corneal layer protein mutations (filaggrine) -> increase in the amount of water lost and facilitate the penetration of allergens

Epidemiology / factors environmental : it is high prevalence (10-20%) among children in industrialized countries level socioeconomic high. hygienist theory : reduced exposure to infectious agents -> modification of the regulation of the innate immune system -> allergy

  • Clinique :

Infant and young child (up & rsquo; to 2 years) :

beginning : in general to 3 month, sometimes earlier

Clinique : lesions are type of acute eczema (4 stages), significant pruritus, in the small, in the form of friction cheek against the sheets, agitation

signs Related : xerosis, hyper-linearity Palmoplantar, chéilite ...

Topography of the injury : key symmetrically convex areas of the face (play, front, menton), fairly clear respect for the midface region (nose, perioral) and members, may spread to neck, scalp, retro-auricular region, flexures, trunk

children from plus from 2 years :

Clinique : the predominant lesions are chronic appearance, cutaneous xerosis is almost constant, more pronounced in winter

Topography of the injury : the lesions are more localized : the folds (elbows, popliteal, neck and under-ear), in some areas stronghold (hands and wrists, ankles, nipples)

Adolescent and adult :

beginning : a late start in adulthood is possible but rare

Clinique : appearance of eczema lichenifie with an array of prurigo, predominant members or nummular eczema or erythroderma

Topography of the injury : more, retroauricular groove, back of hands, perioral region, sometimes lower limbs

  • Evolution :

AT court term : evolution is chronic, made of alternations between exacerbations and remissions according to various aggravating factors, with the possibility of complications. The most classic triggers are : teething, infections, vaccinations, changes in the environment or diet, heat, inadvertent use of soaps and antiseptics, wearing clothing made of wool or synthetic textile, emotions, stress and child annoyances

AT long term : Infant, most of the time, spontaneously favorable (complete remission in a few years), persistent forms in childhood are often more localized, the resurgence or persistence in adolescence or in young adults can

  • Complications : extension of lesions to erythroderma, growth retardation, contact dermatitis

Surinfections : bacterial (staphylococcus), viral (herpes virus : Kaposi Juliusberg varioliform pustulosis which may have a serious course, common wart, molluscum contagiosum)

  • Diagnostic : clinique (+++), given the personal and family history of atopy, age of onset of lesions, appearance and topography of lesions. biological explorations : increased serum IgE and eosinophilia blood

Toutitement :

  • Means local :

Antiseptic : permanganate bath (KMnO4) : 1 tablet 250 mg in 5 liters of water which is used to soak the affected part during 15 minutes

antibiotics local : Fucidine® : crème (exudative lesion), ointment (dry lesion)

Dermocorticoïdes : their level of action and dosage presentation are based seat, aspect, extent of lesions and patient age

Emollient and moisturizing : vaseline simple, urea preparation (Xérial® : 10, 30, 50), moisturizer (water Xeracalm®, Xemose uriage®, Atoderm®…)

inhibitors from the calcineurine topical : Tacrolimus (Protopic®) : ointment 0.03% for the child 2 at 16 years, 0.1% for adults

  • Means general :

antibiotics : avoid β-lactams (allergenic character), we will mainly use macrolides : erythromycin (tablet 500 mg, 2-3 g/j), Rovamycine® (compressed, syrup in children), anti-staphylococciques : Fucidine® (tablet 250 mg and syrup), Pyostacine® (tablet 500 mg, 2 g/j)

antihistamines : Polaramine (syrup, tablet 2 and 6 mg), mequitazine (Primalan®)

corticosteroids : Cortancyl® (tablet 5, 10 and 20 mg) prescribed only in severe generalized eczema

  • Indications :

Treatment from eczema from contact allergic :

Treatment etiological : allergen avoidance (basic therapeutic measure), but the ubiquity of certain allergens makes it difficult eviction

Treatment symptomatic :

corticosteroids locale (Diprosone®, Locoid®, Efficort®…) : pendant 1-2 weeks

corticosteroids General : if over-acute and / or diffuse attack (15-30 mg / day for 3-7 days)

Bains antiseptic and antibiotic General : indicated in case of superinfection

Prevention and followed : in the workplace, relies on wearing gloves, protective clothing, in occupations with high risk of awareness, development workstation in collaboration with the company doctor, there is no possibility of desensitization in contact dermatitis

Treatment from eczema atopic :

Treatment of the outbreaks : dermocorticoïdes (no corticosteroids in AD), topical calcineurin inhibitors, oral antihistamines (anti-H1), antiseptics and local or systemic antibiotics (in case of overt infection)

Treatment maintenance : emollients, hygiene (avoid irritating textiles : laine, synthetic coarse fibers, prefer cotton and linen, avoid exposure to tobacco, maintain a cool temperature in the room and not to cover the night, physical exercises, sports consultant (and shower emollients after), daily short bath, with a warm temperature and breads or gels without soap), attention : contage herpetic ! Vaccination permitted outside outbreaks

Education therapeutic : the patient or relatives, aims to learn to live optimally with chronic illness, to know the aggravating factors, understand and see practical demonstrations of local care ...

Other treatments : phototherapy, cyclosporin, Azathioprine