Pathogenesis clinical features and management of Atopic dermatitis lecture.pptx

Pathogenesis clinical features and management of Atopic dermatitis. It also explores, other skin inflammation, causes and their cures in medicine

1. PATHOGENESIS CLINICAL FEATURES AND MANAGEMENT OF ATOPIC DERMATITIS Onodugo Nkiruka Pauline. 23/11/2021

2. introduction Atopic dermatitis is a chronic inflammatory skin disease associated with cutaneous hyperactivity to environmental triggers that are otherwise innocuous to non atopic individuals and is often the first step in the atopic march that results in asthma and allergic rhinitis. The clinical phenotype that characterizes atopic dermatitis is the product of interactions between susceptibility genes, the environment, defective skin barrier function, and immunologic responses. An understanding of the relative role of these factors in the pathogenesis of AD is important and has implications for therapy

3. PATHOGENESIS

4. PATHOGENESIS Contd.

5. GENETIC FACTORS Twin concordance rate for monozygotic twins is 0.72 and only 0.23 for dizygotic twins. This means environmental factors are implicated in about a third of the cases. Numerous susceptibility loci have been implicated and include 1q21 (locus for gene encoding fillagrin protein) Other genes affected apart from FLG gene include IL4, SPINK5, RANTES,IL18, NOD1, DEFB1 e.t.c Similar to genes associated with other diseases like asthma, COPD, HIV, sepsis, Crohns and sarcoidosis

6. ENVIRONMENTAL FACTORS UV exposure from sunlight and vitamin D production in the skin Tobacco smoking and environmental pollutants Urban and rural dwelling and history of recent travel. Breast feeding and delayed weaning Obesity and physical exercise Family size ,exposure to infective agents ,…..the hygeine hypothesis

7. CLINICAL FEATURES Varied and depend on the age of patients, and phase of the disease. Presentation include: Itching Erythema Papules and vessicle Eczematous areas with crusting Hyper and hypopigmentation Excoriation and lichenification Xerosis Secondary Infections

8. INFANTILE PHASE

9. Infantile phase

10. CHILD HOOD PHASE

11. Childhood phase

12. Hand affectation in AD

13. saliva is a common irritant

14. ADULTHOOD Similar to that in late childhood. Lichenification of the flexure areas may be seen Hand Eczema occurs in up to 50% of adult cases and might be persistent from childhood eczema Nipple eczema, perioral dermatitis and prurigo nodule are all features.

15. INVESTIGATIONS Initial Diagnosis is rarely aided by investigations. Relevant investigation however include: Total serum IgE Skin prick tests Patch test for concomittant ACD Bacteriological and Viral skin swabs and culture and sensitivity testing

16. Histology usually not indicated but show spongiosis , disruption of desmosomes and formation of microvessicles and( exocytosis ) in the acute phase. Chronic form, spongiosis is difficult to appreciate, there is marked acanthosis , hyperkeratosis,hypergranulosis and minimal parakeratosis .

17. DIAGNOSIS Based on history and examination findings . The Hanifin and Rajka major and minor diagnostic criteria is a comprehensive tool for diagnosis of atopic dermatitis. The UK working party diagnostic criteria is a revision of Hanifin Rajka which is simpler to use and suitable for both epidemilogical studies and in the clinic setting.

18. Hanifin and Rajkal diagnostic criteria Major Criteria: Must have three or more of: Pruritus Typical morphology and distribution Flexural lichenification or linearity in adults Facial and extensor involvement in infants and children Chronic or chronically-relapsing dermatitis Personal or family history of atopy (asthma, allergic rhinitis, atopic dermatitis)

19. Hanifin and Rajkal diagnostic criteria Contd. Minor criteria: Should have three or more of the following: Xerosis Ichthyosis,palmar hyperlinearity or keratosis pilaris Immediate type skin test reactivity Raised Serum IgE Early age of onset Tendency towards cutaneous infections (especially S.Aureus and herpes simplex)

20. Minor criteria contd. Tendency toward non specific hand and foot dermatitis Nipple eczema Cheilitis Recurrent conjuctivitis Dennie – Morgan infraorbital folds Keratoconus Anterior subscapular cataracts Orbital darkening

21. HANIFIN AND RAJKA DIAGNOSTIC CRITERIA FOR ATOPIC DERMATITIS CONTD. Facial pallor or facial erythema Pityriasis alba Anterior neck folds Itch when sweating Intolerance to wool and lipid solvents Perifollicular accentuation Food intolerance Course influenced by environmental factors White demographism or delayed blanch

22. U.K. working party’s diagnostic criteria History of pruritus plus 3 or more of the following: Onset under the age of 2 years (not used if child is less than 4yrs) History of involvement of skin creases History of a generally dry skin in the past year Personal history of asthma or hay fever or positive family history in patients <4yrs. Visible flexural dermatitis

23. ASSesing Severity Assesing severity of lesion is part of initial assesment . The best scores being used currently are the EASI and SCORAD scales as they are the most validated scales. They also show good validity, reliability and sensitivity.

24. DifferEntial Diagnosis Other Inflammatory skin conditions Contact dermatitis Pityriasis Alba Psoriasis Seborrheic dermatitis Infections / infestations Impetigo Cutaneous candidiasis Eczema herpeticum Viral exanthem Scabies Rare genetic disorders / immunodeficiency disorders X- linked recessive ichthyosis Non bullous ichthyosis erythroderma Netherton syndrome STAT3 deficiency e.t.c

25. TREATMENT Counselling is a very important and initial treatment strategy Explaining in simple language the aetiology and clinical course of the disease Basic skin care practices. Decrease frequency and duration of baths. The wrinkle sign signals that bath time is already prolonged Identification and avoidance of triggers

26. TREATMENT CONTD. First line Treatment: Emollients Topical corticosteroids (TCS) Anti histamines Antibiotics, antifungal and antiviral agents when necessary Topical calcineurin inhibitors (TCI) for “steroid phobia” or lesions on the face Maintenance :TCS and TCI twice weekly and daily emolients

27. Poor response? Second line treatment: Reassess patient Short course topical potent steroids Review diet in children and intensify search for triggers and re emphasize need for avoidance Consider admission Physical methods like wet wraps and phototherapy (for adults only)

28. Second line treatment contd.

29. Treatment contd.

30. RecAlcitrant disease

31. Third line of treatment

32. Systemic agents for treatment of atopic dermatitis Oral Corticosteroids (Short course) Ciclosporin Azathioprine Methothrexate Mycophenolate mofetil Phototherapy (in adults)

33. SYSTEMIC treatment contd.

34. Concluding remarks A good understanding of the pathogenesis and disease course of AD by the physician translates to better education of the patient and this results in better outcomes. Basic skin care practices and TCS will often suffice

35. However there are resistant cases, and some factors may necessitate use of systemic therapy in some patients. New treatments in development hold tremendous promise in the treatment of AD .

36. THANK YOU FOR LISTENING

37. Major resources Rooks Textbook of dermatology (8 th edition) Medscape Journal of Allergy and Immunology