Download Atopic dermatitis

ECZEMA
Lecture fife
FUNCTIONS OF SKIN
• Protect against infections, chemical toxins
and physical agents (UV, ionizing radiation)
• Prevent insensible water loss
• Control body temperature
(thermoregulation)
• Sensation, communication (psychosocial,
sexual, endocrine functions)
• Self-regeneration and healing
ECZEMA
Usually refers to severely inflamed dermatitis.
•It is a non –infectious inflammatory dermatosis in
which the affected skin is erythematous.
• IT IS NOT ADISEASE, IT IS A SYMPTOM.
MOST DERMATOLOGISTS WOULD ACCEPT THE
DEFINITION: SKIN INFLAMMATION OF WHATEVER
CAUSE
•signs and symptoms associated with such an acute
process (itching, sting, burning of the skin with
drainage from lesions)
TERMINOLOGY
Dermatitis =
Dermat
+
refers to skin
itis
means
“inflamed”
(thus, inflamed skin)
Other examples: arthritis, colitis,
encephalitis, etc.
CARDINAL FEATURES
OF INFLAMMATION
• (warmth) - increased blood flow
• (redness) -dilated blood vessels
• (pain)- irritation of nerves in inflamed
tissues
Classification
• Can either be acute or chronic in nature.
• Acute eczema shows marked inflammation of
skin, erythema and papules
.
• Chronic eczema shows lichenification
(thickening of the skin) from repeated rubbing or
scratching, post inflammatory hyper- or hypo
pigmentation.
• Both types can show excoriations.
• There is commonly a secondary infection,
usually with Staphylococcus aureus (S. aureus).
TYPES OF DERMATITIS
( ECZEMA)
• IT IS PRECIPITATED BY EXTERNALSOURCES
OR INTERNAL ONES(ENDOGENOUS
• Exogenous: contact DERMATITIS(acute)
• Irritant, allergic and infective.
• Endogenous, chronic Atopic, A steatiOTIC,
neurodematisTIS,and other types
•
IRRITANT CONTACT
DERMATITIS
• 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
Miscellaneous
FACTORS INFLUENCING THE
DEVELOPMENTOF SKIN
IRRITATION
• THE SUBSTANCE, IF IT PENETRATE TO THE
DERMAL AREA WHERE VASCULAR AND
LYMPHATIC SUPPLY ARE PRESENT
• DEGREE OF IRRITATION DEPEND ON:
1- THE INTRINSIC IRRITATION POTENTIAL
2-CONCENTRATION
3-ABILITY TO REMAIN BOUND TO THE SKIN
• THE CLIMATE;
• MACRO;WHICH REFERS TO
ENVIROMENTAL CONDITIONSWHICH WILL
AFFECT SKIN TEXTURE
• MICRO CLIMATE DEPENDS ON WETHER
THE SKIN IS OCCLUDED OR LEFT OPEN
TO THE ATMOSPHERE
• THE HOST;
• AGED SKIN IS LESS PRON TO
IRRITATION THAN YOUTHFUL SKIN,
BECAUS E OF GREATER DIFFICULTY
IN DRUG PENETRATION THTOUGH
AGED SKIN
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.
Atopic dermatitis
A chronic problem causing dry skin, intense
itching, and a raised rash, some children outgrow
atopic dermatitis, or have milder cases as they
age. In severe cases, this non-contagious rash
forms clear, fluid-filled blisters. What causes
atopic dermatitis isn't clear, but those affected
may have a personal history of allergies and
asthma and a sensitive immune system. IT
OCCURE PRIMARILY DURING CHILDHOOD
AND EARLY ADULTHOOD
Several treatment options for eczema are
available. But primarily, it is most important to
diagnose correctly and to identify the underlying
etiological factors (e.g. allergens in case of
allergic contact dermatitis). Avoidance of the a
etiological factors is one important therapeutic
approach. Symptomatic treatment includes
topical and systemic treatment regimens. The
treatment depends on the underlying type of
eczema
and
on
its
localization.
The following general guidelines have proved
helpful
in
eczema
patients:
• Asteatotic eczema: this eczema is characterized by
dry and fissured skin and by absence of sebaceous
secretions. It occurs mainly during the dry weather
and in the aged skin.
• Neurodermatitis: this is a chronic form of eczema
found more often in women. It is often localized in the
nape of the neck, legs,genitoanal region, and
forearms.
• Emotional stress play a role in this condition.
Strategy for treatment of eczema
• In some forms of eczema the patient is
sensitive for a wide variety of agents, and
therapeutic entities may aggravate already
inflamed skin.
• In contact dermatitis, drug therapy is
needed for only a short time because
withdrawal
of
allergen
or
irritant
ameliorates the condition
TREATMENT OF allergic cotact
dermatitis
•
•
•
•
•
•
Topical glucocorticoids
Oral antihistamines
Compresses
Topical Emollients
Oral antibiotics
Oral glucocorticoids
CHILDHOOD ECZEMA
OTC products for eczema
• 1- protestants; zinc oxide past (lesser)and
ointment
• 2- astringents ;soaking in solution of aluminum
acetate reduces the weeping for a large areas.
Bathes of local astringents compresses(15-30 )
a few time daily help dry the weeping areas.
More potent astringents should be reserved until
erythemal inflammation of the acute phase
subsides in order not aggravate the condition
3- cooling agents; to reduce the extent of pruritus.
In the acute phases of eczema, soothing lotions
applied as wet compresses are helpful.
4- antihistamines ;orally administered for their
sedative and antipruritis effects.
5- antiseptics; these are useful in infective
dermatitis
preccautions
• calamin lotion and other powered-based
preparations that dry weeping through
water adsorption should be avoided
because of their tendency to crust.
• Removal of the crust may cause bleeding
and potential infections
SUMMARY
Dermatitis is a common type of skin inflammation
There are many causes of dermatitis
Dermatitis disrupts the normal functions of skin
Investigating causes of dermatitis is as important as
using drug therapy
Traditional agents (glucocorticoids, antihistamines)
and newer agents (TIMs) are available to treat this
condition
Thank you