ALLERGIC%20DERMATOSES

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ALLERGIC DERMATOSES
Lector Shkilna M.
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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

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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.

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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)
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TERMINOLOGY

• Dermatitis Dermat itis
• refers to skin means
• inflamed
• (thus, inflamed skin)
• Other examples arthritis, colitis,
  encephalitis, etc.

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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

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Allergic dermatoses
B. Immunologic Spectrum
Non-IgE Mediated
IgE-Mediated

• Oral Allergy Syndrome
• Anaphylaxis
• Urticaria
• Allergic Rhinitis
• Acute Bronchospasm

• Eosinophilic esophagitis
• Eosinophilic gastritis
• Eosinophilic gastroenteritis
• Atopic dermatitis
• Asthma

• Protein-Induced Enterocolitis
• Protein-Induced Enteropathy
• Eosinophilic proctitis
• Dermatitis herpetiformis
• Food-induced Pulmonary Hemosiderosis

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TYPES OF DERMATITIS

• 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

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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.

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• 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.

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Allergic Contact Dermatitis
Figure 19.7
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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

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Nickel

• 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

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Nickel Dermatitis

• 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

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Neomycin Sulfate

• 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

13 year old boy developed an itchy allergic
contact dermatitis from a topical antibiotic.
www.dermatlas.org
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Quaternium-15

• 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

Hand dermatititis due toquaternium-15 in a
moisturiser dermnetnz.org/dermatitis/quaternium
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IRRITANT CONTACT DEMATITIS

• 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

COMMON IRRITANTS

• Water
• Skin cleansers
• Industrial cleaning agents
• Acids and alkalis
• Oils and organic solvents
• Oxidizing and reducing agents
• Plants
• Animal products

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CONTACT DEMATITIS
Allergic contact dermatitis (Nickel)
IRRITANT CONTACT DEMATITIS
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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

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ATOPIC DERMATITISEXACERBATING 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)

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Atopic Dermatitis

• 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, cows milk represent up to 75 of
  positive test.

Clinical Phases

• Infantile Phase ( 0-2 years )
• Childhood Phase ( 2-12 years )
• Adult Phase (puberty onwards)

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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
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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.

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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

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FLARE FACTORS IN ATOPIC DERMATITIS
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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)

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Urticaria

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

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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.
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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.

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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)

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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

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Classification of chronic urticaria
Chronic urticaria
Ordinary chronic urticaria
Physical urticaria
Urticarial vasculitis
Contact urticaria
Schnitzlers syndrome
Autoimmune urticaria
Idiopathic chronic urticaria
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Physical urticaria

• Cholinergic Reaction to body heat, such as when
  exercising or after a hot shower

Dermatographic Reaction when skin is scratched
(very common)
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Delayed Pressure Urticaria reaction to standing
for long periods, bra-straps, elastic bands on
undergarments, belts
Physical urticaria
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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
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Physical urticaria

• Aquagenic urticaria reaction to water

• Heat urticaria reaction to hot food or objects

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• URTICARIAL Vasculitis

Papular urticaria
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Contact urticaria

• Urticaria Pigmentosa (mastocytosis)

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Skin Prick Test (SPT)

• Specific
• Sensitive
• Simple to perform
• Rapid (result in 15-20 min)
• Educational for patient

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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.

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Treatment of urticaria

• 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

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Thank you for your attention!