ATOPIC DERMATITIS “ATOPY” is a genetically determined tendency to produce increased amounts of reagens (IgE), in response to allergens. Clinically manifested by : Clinically manifested by : ASTHMA HAY FEVER ATOPIC DERMATITIS
Macropha ge T cell B cell Plasma cell Antigen IgG IgM IgA IgD IgE IL-1 IL-4 IMMUNITY
Macrophage T cell B cell Plasma cell Antigen IgE IL-1 IL-4 ALLERGY
Major features (must have 4) Pruritus Early age of onset Typical morphology and distribution Infants & Children: Face & extensors Adults: Flexureal lichenification & linearity Chronic course Personal or family history of atopy (asthma, rhino- conjuctivitis, dermatitis).
Minor features Dryness of skin Ichthyosis, palmar hyperlinearity/keratosis pilaris Hand/foot dermatitis Lip dermatitis Nipple eczema Increased cutaneous infections e.g. Staph. aureus & H.Simplex)
Common Clinical Features: Itching Erythematous Macules, Papules, vesicles Eczema with crusting, Lichenification, Excoriation Dry skin Secondary infection
ACUTE vs Chronic AD Acute AD Redness Swelling Papules Vesicles Exudation Cracking Chronic AD Less vesiculation/ exudation More Thickening, pigmentation & Lichenification (due to rubbing & scratching) Fissures Scratch marks
Infantile/childhood AD Red Itchy scaly lesions on scalp, cheeks, wrists & trunk Diaper area spared Extensor aspects of limbs (begins to Crawl) Irritable & restlessness Crusts Pustules Adult AD Lichenified, pigmented papules, plaques scattered all over body Bothering itch Prominent infra-orbital crease General dry skin
Seb. Derm Characterized by: Erythematous scaly plaques Greasy scaling yellow crusted patches & plaques There is very minimal itch (vs AD) Age of onset: Below 06 months: infantile SD After puberty: adult SD
Irritant Contact Dermatitis Non-allergic reaction of the skin caused by exposure to irritating substance Any person can develop ICD if concentration & duration of contact sufficient About 80% of occupational dermatitis is irritant in nature C/F: Erythema, Edema, Vesiculation, Weeping
ALLERGIC CONTACT DERMATITIS Immunologically-mediated, Delayed (type IV) hypersensitivity Occurs in persons already sensitized Not dose related, Not restricted to area of contact C/F: erythema, edema, papules, papulovesicles it is difficult to distinguish C/F of ACD from irritant or constitutional dermatoses(AD, SD) it is difficult to distinguish C/F of ACD from irritant or constitutional dermatoses(AD, SD)
Treatment Principles Avoid known triggers Moisturize, moisturize, moisturize Itch Control Topical corticosteroids Other topical therapies Systemic therapy
Avoid Irritants Allergen avoidance during pregnancy and or infancy (mild benefit shown from avoiding cow’s milk, eggs, and dust mites) Big Five: dryness, dust mites, animal dander, cigarette smoke, wool Others include water and chemicals
Dry Skin Care Baths and showers not hot and short Mild soap (Dove) – best to avoid alkali soaps Blot dry and immediately moisturize (skin should still be slightly damp) Creams and ointments better than lotions and oils
Itch Control Avoid topical antihistamines Products containing menthol, camphor & weak conc: of phenol may be helpful Cool compresses Avoid hot/sweaty conditions
Antihistamines In children generally sedating AH used. No role of non-sedating AH in children with AD A combination of sedating & non-sedating AH indicated in adults with eczema. For AD: Zonalon=topical doxepin – qid for maximum of eight days. Never occlude, some systemic absorption, very sedating, risk of ACD
TOPICAL STEROIDS Steroid 1. Potency 2. Vehicle 3. Amount 4. Site 5. Clinical stage of eczema 6. Weather 7. Duration of treatment 8. Disease
Other Topical Therapies Tar Salicylic acid Topical Tacrolimus, pimecrolimus
Antimicrobials Antibiotics for culture proven infections Ketoconazole for head and neck based atopic dermatitis (reduce yeast counts)
Phototherapy UVB Narrow Band UVB UVA/PUVA Sunlight
Other Therapies Leukotriene Inhibitors do not work Oral cromolyn sodium results conflicting Interferon gamma daily s/c inj. helps Cyclosporine Azathioprine Hydroxychloroquine
Some Specific Types of Eczema
Discoid/Nummular eczema Circular or oval plaques A clearly demarcated edge Related to atopy, emotional stress, bacterial infection Usually lesions dry. Exudative ones always associated with bacterial infections. Treatment: Emollients, topical steroids, antibacterials
Lichen Simplex Chronicus An eczematous dermatosis characterized by Lichenified plaques, usually 1-2 in number Typical sites: nape of neck, scrotum, wrists skin thickened, pigmented with prominent skin markings Associated with atopy, emotional stress Tr: Superpotent steroids with keratolytic agents. I/L steroid injections
Nodular Prurigo Characterized clinically by chronic, intensely itchy papules & nodules lesions range from small papules to hard nodules, 1–3 cm in diameter, with a raised, warty surface. The early lesion is red later becoming pigmented. Tr: superpotent steroids, oral steroids, UVB, PUVA, thalidomide
Pompholyx Pompholyx is characterized by the sudden onset of clear vesicles over hands. Symptoms: No erythema, less pruritus but more heat and prickling sensation. Sites: sides and dorsa of fingers & hands Vesicles may become confluent and present as large bullae, especially on feet. Itching may be severe, preceding the eruption of vesicles
Pityriasis Rosea (P. rosea) An acute, self-limiting disease, probably infective in origin, affecting mainly children and young adults. The first lesion is “Herald patch” a large circular, sharply defined eryhematous patch with fine scales on thigh/trunk. This is followed by an eruption of discrete oval lesions, dull pink in colour, covered by fine, dry, silvery scales forming a collarette at edges. The centre tends to clear and assumes a wrinkled, atrophic appearance. The lesions appear in crops.
P.Rosea contd……. The lesions tend occur in ‘chrismas tree’ pattern along the rib cage. There are usually no symptoms. Some pts. have mild to moderate pruritus Tr: The common asymptomatic, self-limiting cases require no treatment. If itch is severe or the appearance distressing, a topical steroid (moderate potent) or UVB can be helpful.
Asteototic Eczema Eczema developing in dry skin Seen on legs, arms and hands. Tends to be more marked in the winter and in elderly people. Skin is dry, scaly showing a criss-cross skin markings. Finger pulps are dry and cracked; retaining a prolonged depression after pressure (‘parchment pulps’). Associated with hypothyroidism, zinc deficiency, diuretic use and cimetidine use
Pityriasis alba A mild eczema in which hypopigmentation is the most conspicuous feature. (NO CALCIUM Deficiency Predominantly seen in children b/w ages of 3 -16 ys. The individual lesion is circular, oval or irregular hypopigmented patch with NOT well defined edges. Lesions often slightly erythematous & have fine scale Common sites: cheeks & around the mouth & chin Less commonly on neck, arms, shoulders & trunk. D/D: vitiligo, P. versicolor, PIH Tr: mild steroids, emollients
DiseaseTypical morphologyDiagnostic clues Irritant CD Allergic CD Atopic Dermatitis Sebhorroic dermatitis Xerotic/asteot ic eczema Nummular /discoid eczema Pompholyx Sharply demarcated macular erythema, little vesiculation Exzematous, scaly edematous plaques with vesiculation Eczematous, honey-crusted scaly plaques, lichenified in chronic cases Greasy scaly papules, minimal itch Crackled parchment like patches, no edema, no vesiculation Coin-shaped, well demarcated, scaly or weepy plaques, bilateral, symetrical, kissing lesions Deep seated papulo-vesicles on palmar plantar surfaces, volar edges More burning less itch, only at area of contact Pruritis, primary lesion at area of contact, Flexural areas, neck predominance Hair bearing areas, glabella, nasolabial folds Lower legs Arms, legs, dorsal hands Palms, soles, typical dorsal involvement
Conclusions Eczema management rests on three pillars: avoid irritants, moisturize, topical management Use steroids to quiet a flare then switch to a nonsteroidal therapy Treating hot spots can prolong remissions Control itch!
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