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Dermatology
د. سهام
Eczema (Dermatitis)
It is 2nd most Common disease after infection Eczema is inflammatory response of skin to various endogenous or exogenous agent many types of eczema remain unknown or multifactorial. There is no accepted universal classification almost always itchy. Classification according to etiology – site – shape: 1- Exogenous Irritant 1- Contact Allergic 2- Photo 3- Infectious 2- Endogenous 1. Atopic dermatitis 2. Soeboric dermatitis (from sebecious gl. aff . scalp, face, genitalia, axilla, in winter less in summer) it is not due to increase in sebum, newborn can aafected by Soeboric dermatitis & anti-fungal need for Rx 3. Discoid (nummular) dermatitis (severly itchy mainly in extremities) 4. Stasis (gravitional) in varicosity 5. Pityriasis alba abt 2% present in our society chara by hypopigmentation, scaley, more in children in summer time 3- Unclassified 1. asteatotic dermatitis. 2. Juvenile plantar dermatitis. 3. Lichen simplex chronicus. 4. Chronic scaly superficial dermatitis.
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Histopathology
Clinically eczema classified: 1- Acute 2- Sub acute 3- Chronic 1- Acute:- edema in epidermis (spongiosis) Formation of intraepithelial vesicles. Coalesce to large blister 2- Chronic:- Less spongiosis and vesiculation thickening of prickle cell (acanthosis) and horny layer hyper keratosis and Para keratosis and variable degree of vasodilatation and lymphocyte infiltration. 3- Sub acute stage:- changes to acute and chronic at same time with obvious hyper keratosis and Para keratosis.
Clinical feature 1- Acute: - redness – swelling with ill defined border – papules. , vesicles and – even – large blisters – exudation – crusting and – scaling. 2- Chronic: - less vesiculation and less exudation and more – scaly formation, skin pigmented and thickened – more likely to be Lichenified (thickened) pigmented skin + exaggerated skin marking Lichenification: is dry thickened with increase skin marking secondary to repeated scratching and rubbing.
Contact dermatitis
- It is an inflammatory response of skin induced by substance that contact skin surface and responsible substance Could be solid liquid or gas. - The substance acts as irritant or allergic and may cause acute, subacute and chronic inflammation. - This disease is common in our city.
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Comparision. between – Allergic & irritant contact dermatitis
People at risk Irritant Every – one Non – immunologied Physical or chemical alteration of epidermis & structural damage. Allergic Genetically predisposed Delayed Hypersensitivity Reaction. One or several to cause sensitization. Low m.tw hapten May be very low
Mechanism
No. of exposure Few to many depends on individual ability to maintain epidermis barrier Nomber of sub Conc. of subs required Distribution Organic solvent & soaps. Usually high
Border usually indistinguished not spread. Gradual Trial of avoidance
Border exactly to contact ant Rapid Trial of avoidance Patch test or Both
Mode of onset Investigation
-Irritant substance could be so irritate that leads to Dermatitis with the 1st touch to skin & some are weak and need to be repeated many times to cause eczema. -Allergic Dermatitis Needs the 1st contact to develop lesion and on the second contact will develop allergic contact Dermatitis which is Delayed type hypersensitvity reaction and intensity of the inflammation depends
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on the degree of sensitivity and the pattern of inflammation is exactly similar to the shape of offending substance.
Dx of contact Dermatitis
1- Medical History Date of onset Relation to work 2- Physical examination Distribution – shape of lesion. 3- Patch test: When – inflammation persist This test useful for allergic contact dermatitis.
Atopic Eczema
Definition; -Are common, chronic, and very pruritic skin diseases occuring In individuals with hereditory tendency to atopy. -70% of the patient's have a positive family history of atopic disorders. -15% of populations have at least one of the atopic diseases. -80% of the patient's have a high level of IgE and impaired cell impaired cell mediated immunity. -Atopy means "not in its place " and clinically atopy is the genetic predisposition to react immunologically abnormal to certain agents.
Stage of atopic dermatitis There are 3 stages 1- Infantile 2- Child hood 3- Adult hood
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Dermatitis Infantile stage
- Age of onset is (3/2 month – 2 year). - Tends to be vesicular and weeping which starts on the face but sparing the napkin area. - It is does not occur before 3 months of life because the immune system does not well develop untill the 3rd month of life - It usually affects the face, cheeks, and forehead in which vesicular crusted eruptions appear usually with secondary bacterial Infection due to scratching, it may involve the whole body surface, it may last months to 2 year and 1/3 of Patients pass to child hood stage and end by – 2 year.
Child hood
- It affects mainly flexures(folds), anticubital and neck which have subacute and chronic manifestation of eczema. - Skin becomes dry and excoriated elbows and knees, flexures(wrists and ankles) and neck usually bilateral and very pruritic - Atopic dermatils could be very mild or very severe starting with short period or whole life.
Adulthood stage
(Disseminated Neurodermatitis)
- Flexures (neck, eyelid, Genitals) involved but start to disseminate and skin show marked tendency to Lichenification with more wide and spread. - It is chronic type of eczema.
Diagnosis
1- History & C/p 2- Biopsy show dermatitis
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Treatment
1- Explanation and reassurance and encouragement 2- Elimination or prevention of trigger factors - Excessive heat sweaty - Soaping of skin - Wool - Infection else where psychotic stress 3- Control of Itching by a sedative antihistamine and stop the child from scratching during sleeping. Control of Inflammation by topical steroid 4- Control the inflammation by Topical steroids but It is contraindicated to use potent steroids so usually use weak steroids 5- Control of secondary infection by topical and systems antibiotic. General Instruction 1- Wear loose cotton clothing 2- Keep finger nail trimmed short or wear gloves In children and infant to prevent scratching 3- Avoid heat 4- avoid frequent Course It is variable Impledictable and may disappear a long time Prognosis 1/3 of infants pass to child hood And 1/3 of child hood pass to adult stage
Pityriasis alba
- It occurs predominantly In children. - A rounded, oval or "regular" defined plaque which is red, pink or skin colored with fine lamellar or branny scaling patches are usually Multiple may be 4 or 5 or 20 or more. - Lesions are confined to the face in 50-60% however neck, arm and shoulders are also involved, and it is common among atopics.
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- Lesions are symptomless and the most cases persist for some months or a year. -Treatment: 1- Blend emollient cream 2- Mild topical steroid (hydroCortisone) cream 1%
Pompholyx
May occur at any age but It is more common In warm weather It affect palms and soles – sudden onset of clear vesicles which deeply seated vesicles may become confluent and present as large bullac – Itching may be server the attack subside spontaneously and resolution with desquation occur in 2.3 weeks. Treatment 1- Hands and feet should be soaked 3-4 times a day in solution of normal saline or potassium permanganate wet dressing Large bullae may be opened. 2- Antibiotic should be used (systemic antibiotic) 3- Topical corticosteroid cream. 4- Anti Histamine.
Localized neurodermatitis
(Lichen simplex chronicus)
- It is an eczematous eruption characterizedby repeated rubbing, scratching of a single localized area as a habit but there is no any underlying skin disorder. - It is more common in middle age group. - Psychological stress, external factors, and systemic diseases lead to Itching which in turn make the patient rub and scratch the skin and cause Lichenification. - Lesion is single(Fixed Lichenification). - Plaque is found on head, fore arm, Neck, Leg, Genitals, Lower part of Leg, and Nape of neck.
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Treatment: 1- Stop scratching or rubbing. 2- Potent topical steroids. 3- Occlusive bandaging to prevent Itching 4- Intralesional triamcinolone.
Gravitational eczema
(Stasis eczema)
-Occur in patients with oedema of Legs due to Cardiac, hepatic, renal or varicose inside of ankle and lower Leg as result of underlying Insufficient removal or drainage. -Skin is suscibtible to Irritation and it is the site of secondary Infection and ulcer. -It is common in middle age women with predisposing factors Pregnancy, obesity, thrombophlebitis.
Treatment:
1- Elimination of oedema by elevation and pressure bandage during day time or by diruretics. 2- Topical steroids of moderate potency but put in mind infection is common and antibiotic is needed.
Juvenile plantar Dermatitis
- It is common among children, very few cases have been reported in adult or infants. Clinical feature: 1- Redness and pain in the planter surface of the forefoot which assumes a glazed and cracked appearance. 2- The condition is more severe on the ball of the foot and toe pads and spare non-weight bearing in step, the toe clefts are normal, rarely the disease affects the hands.
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- Treatment:
- Most cases cure spontaneously. - Parents and children should be advised to change footwear to 100% cotton soaks and leather shoes. - In severe cases with cracking and exudation, bed rest may be needed - Topical preparation steroid, urea preparation may help
Infective eczema
- Refers to eczema that is caused by contact with microorganisms or their products. - There is erythemas with Exudation and crusting accumulation of lagre of greasy moist scales beneath which the surface is raw and red and sharply defined and there may be pustules in the advancing edge. - Infective dermatals is seen in the flexures or around discharging wounds or ulcers. -Retroauricular dermatitis Develops which is chronic fissuring and crusting behind the ears of young girls and order women, friction from ear pieces or occlusion by on unsuitable hairstyle, dermatitis limited to the folds behind ears but redness scales and crusting can extend to the neighbouring scaly areas.
Discoid eczema (Nummular eczema)
- Nummular (coin) eczema is a coin shaped high Itchy plague clinically featured, thin walled vesicles on an erythematous base which arises rapidly from the confluence of tiny papules and papulovesides. - In the acute phase the lesions are red oozy crusted and highly irritable they progress towards a less vesicular clearing and peripheral extension causing a ring-shaped or annular lesion. - Two types occur which are moist and dry. - It occur in young adults on extensor surfaces of the hand, limbs or feet
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Aetiology: Unknown
-Factors: 1- Atopic predisposition. 2- Stress. 3- Reaction to bacterial agents.
Treatment:
1- Topical steroids, depend on the age site and duration 2- Antihistamine and antibiotics.
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