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ALLERGIC DERMATOSES

ALLERGIC DERMATOSES. Lector: Shkilna M. Content. 1. Allergic diseases 2. Contact dermatitis 3. Atopic dermatitis Clinical Phases Treatment of atopic dermatitis 4. Urticaria C auses of urticaria Classification of urticaria Treatment of urticaria. WHY DO WE GET ALLERGIES?.

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ALLERGIC DERMATOSES

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  1. ALLERGIC DERMATOSES Lector: Shkilna M.

  2. Content 1.Allergic diseases 2. Contact dermatitis 3. Atopic dermatitis • Clinical Phases • Treatment of atopic dermatitis 4. Urticaria • Causes of urticaria • Classification of urticaria • Treatment of urticaria

  3. WHY DO WE GET ALLERGIES? Immune system designed to protect from life-threatening infection. Co-evolution of components of the immune system with common pathogens Viruses Protozoae & Helminths Bacteria Fungi Evolutionary pressure has generated an immune system able to respond to these diseases.

  4. Important questions in allergy The main topics of concern Food safety (allergenicity of food: composite and genetically modified foods) Chemical factors (products highly aggressive for the skin medication) Biological factors (safety of vaccination)

  5. TERMINOLOGY Dermatitis = Dermat + itis refers to skin means “inflamed” (thus, inflamed skin) Other examples: arthritis, colitis, encephalitis, etc.

  6. Allergic dermatoses A. Nonimmunologic Toxic / Pharmacologic Non-Toxic / Intolerance • Bacterial food poisoning • Heavy metal poisoning • Scromboid fish poisoning • Caffeine • Alcohol • Histamine • Lactase deficiency • Galactosemia • Pancreatic insufficiency • Gallbladder / liver disease • Hiatal hernia • Gustatory rhinitis • Anorexia nervosa

  7. Allergic dermatoses B. Immunologic Spectrum • Oral Allergy Syndrome • Anaphylaxis • Urticaria • Allergic Rhinitis • Acute Bronchospasm Non-IgE Mediated IgE-Mediated • Eosinophilic esophagitis • Eosinophilic gastritis • Eosinophilic gastroenteritis • Atopic dermatitis • Asthma • Protein-Induced Enterocolitis • Protein-Induced Enteropathy • Eosinophilic proctitis • Dermatitis herpetiformis • Food-induced Pulmonary Hemosiderosis

  8. Allergic contact dermatitis Irritant contact dermatitis Atopic dermatitis Other types IT IS PRECIPITATED BY EXTERNAL SOURCES OR INTERNAL ONES (ENDOGENOUS or EXOGENOUS) Exogenous: contact DERMATITIS (acute) Irritant, allergic and infective. Endogenous: chronic atopic dermatitis, neurodermatis, and other types TYPES OF DERMATITIS

  9. Contact Dermatitis • Cell mediated reaction involving sensitized T lymphocytes. • Etiology • Irritant form: Chemical insult to skin. No previous sensitizing event. • Allergic form is delayed-hypersensitivity reaction. Skin sensitized from initial exposure. During next exposure patient has reaction.

  10. Allergic contact dermatitis • The term “contact dermatitis” describes an inflammation of the skin caused by contact with external agents. • Allergic contact dermatitis is a delayed-type hypersensitivity reaction due to the contact with a chemical to which the individual has previously been sensitized. • Possible allergens are found in jewellery, personal care products, topical medications, plants and work-related materials. • Usually, the eczematous reaction develops within 24 to 72 hours after contact with the causative chemical in a sensitized individual.

  11. Allergic Contact Dermatitis Figure 19.7

  12. COMMON ALLERGENS Nickel Jewelry, foods Benzocaine anesthetics Fragrance perfumes, personal care products Mercaptomix rubber gloves Black rubber mix rubber gloves PPD black hair dye Potassium dichromate leather, spackling, detergents Cinammic aldehyde fragrance, toothpaste Quaternium 15 preservative personal care products

  13. Most common allergen tested by the NACDG, with 14% of patients reacting to it Relevance has been estimated to be 50% Commonly used in jewelry, buckles, snaps, and other metal-containing objects High rate of sensitivity attributed to ear piercing Dimethylglyoxime test to determine if a particular item contains nickel Individuals with nickel allergy should avoid custom jewelry, and can usually wear stainless steel or gold Nickel

  14. Common presentations are dermatitis on the ears, under a necklace or a watch back, or on the mid-abdomen caused by a belt buckle, zipper, or snap Eyelid dermatitis from metal eyelash curlers can be seen Photos from dermatlas.org Nickel Dermatitis

  15. Most commonly used topical antibiotic Most common sensitizer among topical antibiotics Found in many OTC preparations: bacterial ointments, hemorrhoid creams, and otic and opthalmic preparations Frequently used with other antibacterial agents, such as bacitracin and polymyxin, as well as corticosteroids Co-reactivity is commonly seen with neomycin and bacitracin Neomycin Sulfate 13 year old boy developed an itchy allergic contact dermatitis from a topical antibiotic. www.dermatlas.org

  16. Preservative that is an effective biocide against Pseudomonas, as well as other bacteria and fungi Most common preservative to cause ACD Found in shampoos, moisturizers, conditioners, and soaps 80% of those reacting to quarternium-15 are also formaldehyde sensitive Quaternium-15 Hand dermatititis due toquaternium-15 in a moisturiser dermnetnz.org/dermatitis/quaternium

  17. Non-immunologic inflammatory reaction of the skin due to an external agent Varied morphology Clinical types Chemical burns Irritant reactions Acute irritant contact dermatitis Chronic irritant contact dermatitis Water Skin cleansers Industrial cleaning agents Acids and alkalis Oils and organic solvents Oxidizing and reducing agents Plants Animal products IRRITANT CONTACT DEMATITIS COMMON IRRITANTS

  18. CONTACT DEMATITIS Allergic contact dermatitis (Nickel) IRRITANT CONTACT DEMATITIS

  19. Atopic dermatitis • Atopic dermatitis is a chronic inflammatory disease of the skin primarily seen in the pediatric age group • Characterized by dry skin, pruritus, erythema, edema, scaling, excoriations, oozing, lichenification • Increasing prevalence, rising costs • Together with asthma and allergic rhinitis forms part of the ‘atopic triad’

  20. ATOPIC DERMATITIS:EXACERBATING FACTORS(TRIGGERS) • Anxiety/stress • Climatic factors • Temperature • Humidity • Irritants • Detergents/solvents • Wool or other rough material • Perspiration • Allergens (contact, inhalant & food) • Infections (staph and strep)

  21. High level of IgE antibodies to House dust mites IgE bound to Langerhans cells in atopic skin Food exacerbates symptoms in some patients: eggs, peanuts, cow’s milk represent up to 75% of positive test. Infantile Phase ( 0-2 years ) Childhood Phase ( 2-12 years ) Adult Phase (puberty onwards) Atopic Dermatitis Clinical Phases

  22. Infantile ( 0-2 years ) Atopic Dermatitis • 60% of case AD present in the first year of life, after 2 months of age • Begin as itchy erythema of the cheeks • Distribution include scalp, neck, forehead, wrist, and extensors • May become desquamate leading to erythroderma. Egg, peanut, milk, wheat, fish, soy, and chicken may exacerbate infantile AD

  23. Childhood ( 2-12 years ) Atopic Dermatitis • Characterized by less acute lesions • Distribution: antecubital and popliteal fossae, flexor wrist, eyelids, and face. • Persistent rubbing and scratching leads to lichenified plaques and excoriations • Severe atopic dermatitis involving more than 50% of body surface area is associated with growth retardation.

  24. Adult (puberty onwards) Atopic Dermatitis • Distribution: antecubital and popliteal fossae, the front side of the neck, the forehead, and area around the eyes. • Atopic individuals are at greater risk of developing hand dermatitis than are the rest of the population • 70% develop hand dermatitis some times in their lives

  25. FLARE FACTORS IN ATOPIC DERMATITIS

  26. TREATMENT OF ATOPIC DERMATITIS • Identify and control “flare factors” • Topical treatments • Glucocorticosteroids • Newer “non-steroidal” TIMs • Emollients • Moisturizers • Baths with added lubricants • Systemic treatments • Oral antihistamine (a cornerstone of treatment) • Oral antibiotics • Systemic steroids • Immunosuppression (phototherapy, cytotoxic drugs)

  27. Urticaria • Urticaria affects up to 2% of the population at some time in a lifetime • Transitory (individual episodes < 24h duration) red skin swellings with itching • No desquamation, rarely affects mucous membranes • Associated with angioedema in about 40% of cases

  28. SYMPTOMS of Urticaria:- • Intense itching.• Burning.• Sense of heat. LESION • Starts as red erythematous macules.• Soon paleoedematous wheals develop. • Irregular, asymmetrical.• Velvetty to touch.• Erythema well defined, fades on pressure.• Subside within few hours without leaving any trace.• Dermographism positive.• Wheals develop along line of scratching or pressure.

  29. Pathogenesis • In urticaria, a chemical called histamine is released from the cells in our skin. This causes fluid from blood vessels underneath the surface of our skin to leak out. This results in the raised patches (weals) that you see on the surface of our skin. • The histamine also causes the weals to itch. • If urticaria affects the deeper layers of skin, it can cause even larger swellings, called angioedema. • Urticaria and angioedema can occur together or separately.

  30. What are the causes of urticaria? • Allergy (foods such as nuts & shellfish, pollen, exposure to animals, bee stings etc.) • Medications (such as aspirin, penicillin etc.) • Insect bites (papular urticaria) • Infections (viral, bacterial, fungal) • Chemical • Stress • Autoimmune • Heat or cold • Sun (solar urticaria) • Exercise (Cholinergic urticaria) • Pressure (from tight fitting clothing) • Water (aquagenic urticaria) • Vibrations • Idiopathic (unknown)

  31. Differentiating Acute from Chronic Urticaria (Hives) • Acute Urticaria (Hives) • Duration of few days to few weeks • Incidence of 15-20% of population • Etiology usually detected • Most cases are mild and never seen by physician • Chronic Urticaria (Hives) • Duration greater than six weeks • Ranges from continuous (almost daily) to recurrent (symptom free intervals of days to many weeks) • Course variable from months to years • Incidence of up to 3% of population • Etiology not found in 90-95% of cases = IDIOPATHIC (cause unknown or not determined) Chronic urticaria is further subclassified into several distinct entities

  32. Classification of chronic urticaria Chronic urticaria Ordinary chronic urticaria Urticarial vasculitis Physical urticaria Contact urticaria Schnitzler’s syndrome Autoimmune urticaria Idiopathic chronic urticaria

  33. Cholinergic: Reaction to body heat, such as when exercising or after a hot shower Physical urticaria Dermatographic: Reaction when skin is scratched (very common)

  34. Physical urticaria Delayed Pressure Urticaria: reaction to standing for long periods, bra-straps, elastic bands on undergarments, belts

  35. Physical urticaria Solar urticaria: Reaction to direct sunlight (rare, though more common in those with fair skin) Cold urticaria: Reaction to cold, such as ice, cold air or water - worse with sudden change in temperature

  36. Physical urticaria Aquagenic urticaria: reaction to water Heat urticaria: reaction to hot food or objects

  37. URTICARIAL Vasculitis Papular urticaria

  38. Contact urticaria Urticaria Pigmentosa (mastocytosis)

  39. Skin Prick Test (SPT) • Specific • Sensitive • Simple to perform • Rapid (result in 15-20 min) • Educational for patient

  40. Intradermal Skin Test (IDT) • More sensitive than skin prick test • May induce false positive reactions • May induce systemic reactions • Should be done only if skin prick test is negative and allergen is highly suspect.

  41. Avoid provoking factor Oral antihistamine : H1 BLOCKER: - Sedative antihistamine DIPHENHYDRAMINE, HYDROXYZIN, PROMITHAZINE, TRIPROLIDIN Low sedative antihistamine: - ASTEMIZOLE, TERFINADIN, LORATIDIN, CETRIZIN, DESLORATIDIN Doxepin H2 BLOCKER In acute sever urticaria we can start Treatment by IM antihistamine , I.V. steroid {hydrocortisone} and S.C. adrenaline Systemic steroids Topical Treatment usually CALAMIN lotion Resistant chronic urticaria as CYCLOSPORIN, METHOTREXATE Leukotrein receptor antagonist: Zafilukast, Montelukast Treatment of urticaria

  42. Thank you for your attention!

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