Eczema (Dermatitis)
ObjectivesTo define eczema.
provide a classification to eczema.
Outline the treatment of common eczema.
Summarize the principles of steroid use.
(Eczema) is a Latin ward means boil out (ec=out,zema=boil). Eczema=Dermatitis=inflammation of skin.
Eczema is an inflammatory disorder of the skin due to an exogenous or endogenous cause. It may be acute, subacute, or chronic. Clinical presentation of eczema:
Clinical presentation of eczema in general composed of three main features:
itching. itching
Erythema.
Scaling.
They are often called the triangle of eczema.
Erythema scaling
These features vary according to the type and stage of eczema
Stages of eczema:
1-Acute: Itching, intense erythema, oedema, oozing surface vesiculation (or blister formation) erosion crusting.
2-Subacute: Itching, dull erythema & scaling.
3-Chonic: Itching, milder erythema, scaling, dryness, lichenification± fissuring.
Dermatopathology:
Upper dermal oedema, vasodilatation &inflammatory cells infiltration in the dermis.
Spongiosis (intercellular oedema of epidermis) which is the hallmark of eczema sometimes with spongiotic vesiculation especially in the acute stage.
3-Focal parakeratosis.
4-In its chronic state: acanthosis & hyperkeratosis.
Diagnosis of eczema
Diagnosis of eczema is mainly clinical. Investigations are rarely needed.
Treatment of eczema in general
A-general measures:
1-Explain the disease and reassure the patient.
2-Identify and remove the etiologic agent whenever possible as in contact dermatitis.
3-Tell the patient to avoid scratching because it exacerbates eczema and increase liability for infection.
B- Topical therapy:
Topical steroids: used according to the type, stage, severity, age of the patient, and site of involvement.
For mild cases: mild steroid like hydrocortisone 1% or 2.5%.
For moderate cases: moderate steroid like betamethasone valerate 0.1%.
For severe cases: potent steroid like clobetasol propionate 0.05%
*The preparation differs according to the stage of the disease: [the rule is to use the wet for the wet & dry for the dry]
For acute stage (wet): use water base preparations like lotions (especially for hairy area) or creams.(water will evaporate & promote dryness)
For chronic stage (dry): use oil base preparations like ointments (has emollient effect though occlusion)
NB: Avoid potent steroid in (3Fs): Face, Flexors, & infants.
NB: Avoid use of more than 200gr.of mild, 50g. Of moderate & 25gr.of potent steroid per week.
Topical antibiotics: used whenever infection is suspected like mupirocin 2%.
C-Systemic therapy:
Oral H1 antihistamines for pruritus: either sedating like diphenhydramine (allermin) 25mg. Tab. Or nonsedating like loratadine 10mg. Tab. Once or twice daily.
Oral antibiotics (cloxacillin, erythromycin) especially for infected eczema.
systemic corticosteroids may be indicated in severe cases,
Prednisone: two-week course, 1 mg/kg. initially, tapering by 5 mg daily.
Classification of eczema
There are many classifications for eczema; one of them is the aetiological classification. The exogenous eczema is the eczema that occurs in response to external stimuli; while endogenous eczema the constitution of the patient predispose to it.
A-ENDOGEOUS ECZEMA
Atopic eczemaSeborrhoeic eczema.
Discoid (nummular) eczema
Pompholyx (dyshidrotic eczem).
Nurodermatitis
Varicose (stasis) eczema
Asteatotic eczema
Pityriasis alba.
B-ExOGEOUS ECZEMA
1-allergic contact dermatitis
2-Irritant contact dermatitis
photodermatitis.
Infective dermatitis.
Radiodermatitis.
Exogenous Eczema
Contact dermatitisContact dermatitis is an acute or chronic inflammatory reaction to substances that come in contact with the skin. Contact dermatitis is of two types: irritant and allergic contact dermatitis.
DIFFERENCES BETWEEN IRRITANT AND ALLERGIC CONTACT DERMATITIS
ALLERGIC CONTACT DERMATITIS
IRRITANT CONTACTDERMATITIS
1-Occure in genetically predisposed people
May occur in anyone.
2- Caused by an antigen (allergen) usually very low molecular wt. substance (hapten).Such as Neomycin, Procaine, benzocaine, Sulfonamides, Terpentine, Formalin, Mercury, Chromates, Cement, industrial oils, Nickel sulphate, Cobalt sulphate.
is caused by a chemical agent that is toxic to the skin such as acids or alkali in a sufficient concentration & duration of exposure(so even the weak acids & alkali can cause IR.CD after long duration of repeated exposure) (e.g., detergents, phenols, kerosene, organic solvents, sodium and potassium hydroxides, lime, acids)..
3-There is an immunological reaction: a classic, delayed, cell-mediated hypersensitivity reaction*.
Non immunological inflammatory reaction.
4-Need for previous exposure (sensitization).
No need for previous exposure.
5-There is delay time for sensitization.
No delay time.
6- confined to site of exposure; spreading may occur.
Sharp, strictly, confined to site of exposure.
7-Patch test could be used.
Patch test not useful.
8- Total avoidance of causative agent is necessary.
Even decreasing the exposure is useful.
*Delayed, cell-mediated hypersensitivity reactionVI: in allergic CD. Langerhans cell, which processes the antigen, migrates from the epidermis to the draining lymph nodes where it presents the antigen in association with MHC class II molecules to T cells which then proliferate. Sensitized T cells then leave the lymph node and enter the blood circulation. Thus all the skin becomes hypersensitive to the contact allergen. The specially sensitized T-effector lymphocytes produce variety of cytokines resulting in more severe inflammatory reactions.
Patch Tests: used to detect the causative agents in allergic contact dermatitis; application of known allergens to the back of the patient & left under occlusion to be seen after 48&96 hr.s. A positive patch test shows erythema and papules, as well as possibly vesicles confined to the test site.
Contact dermatitis may occur as an occupational disease. Site of exposure gives a clue about the causative substance such as hair dies, make up, detergents perfumes, clothes, shoes...etc. people liable for C d. are house wives, doctors, barbers, building workers...etc
Treatment: Is the same but avoidance of the exposure to the causative substance is necessary.
Photo dermatitis: many patient have photo aggravation of their cd. Or develop the dermatitis only upon exposure to light, so the site of dermatitis will be modified to involve mainly the sun exposed parts s. a.:face, hands, forearms; with sparing of shaded areas s.a. under the chin. photopotection is necessary for Rx.
Housewife's dermatitis:
It is CHRONIC IRRITANT CONTACT DERMATITIS OF THE HANDS it results from repeated exposures to toxic or subtoxic concentrations of offending agents (like detergents) and is usually associated with a chronic disturbance of the barrier function due to repeated rubbing of the skin & prolonged soaking in water, that allows even subtoxic concentrations which in normal skin, if applied only once, do not elicit a reaction to penetrate into the skin and elicit a chronic inflammatory response. Present in form of itching, erythema dyness, roughness,scaliness&fissuring.
Rx: (same Rx) with stopping exposure or using gloves
Cement contact dermatitis:
Another example is the hand eczema seen in bricklayers. In these persons, hand eczema is usually a combination of chronic irritant contact dermatitis (to alkaline medium of cement, sand& rubbing) and allergic CD. (to chromate in cement).
Rx: (same Rx) with stopping exposure or using gloves.
Napkin (diaper) dermatitis
This is a primary irritant effect of body fluids on the skin. The eruption is essentially confined to the area in contact with the diaper (between the umbilicus & mid thigh. It is very common in infancy (but could affect old people who use diapers).It is caused by contact with urine & faeces ( bacteria in the last split urea (in urine) to ammonia which is very irritant. The infant is irritable the area (especially convex areas) is intensely errythematous, macerated ± papules, vesicles& ulcers.
DDx:1-candidiasis which often accompany it.
2-seborrhoeic dermatitis.
3-Tinea cruris.
4-Bacterial infections
5-Inverted psoriasis.
Rx.: avoid using occlusive diapers, keep the area clean &dry ,use mild topical steroid(hydrocortisone cream 1%) along with topical antifungal(like miconazole cream.
Infective dermatitis: eczema occurring secondary to an infection eg. Ear infection leads to otorhoea leads to irritation& eczema around the ear. This to be differentiated f. (infected eczema) in which the eczema is the primary lesion.
ENDOGEOUS ECZEMA
Atopic Dermatitis
Definition: Atopic dermatitis (AD) is a type of endogenous eczema that has the following major criteria:
Chronic or chronic relapsing.
Pruritic inflammation of the skin.
It's distribution differs according to the age group
often occurring in association with a personal or family history of atopy( hay fever, asthma, allergic rhinitis, or atopic dermatitis.)
Increased level of IgE.
Pathophysiology:
Type I (IgE-mediated) hypersensitivity reaction occurring as a result of the release of vasoactive substances from both mast cells and basophils that have been sensitized by the interaction of the antigen with IgE (skin-sensitizing antibody); through which an eczema-like reaction could be mediated.
Sex: Slightly more common in males than in females.
Hereditary Predisposition: Over two-thirds of patients have a personal or family history of atopy, with maternal penetrance stronger than paternal. First male baby in the family is more vulnerable to have the disease.
Skin Symptoms Patients have dry skin. Pruritus is the sine qua non of atopic dermatitis—“Eczema is the itch that rashes.”
INFANTILE ATOPIC DERMATITIS
Age: in first 2 months TO 2 years of life.Skin Lesions: Itching, intense erythema, oedema, oozing surface vesiculation erosion crusting. Infant usually irritable.
DISTRIBUTION Regional, especially the face, and the lateral aspects of the legs, with similar involvement (to a lesser degree) on the trunk and arms. Condition may resolve or pass to:
CHILDHOOD-TYPE ATOPIC DERMATITIS
May evolve from infantile AD. Or starts de novo.
Skin Lesions: Papular, scaly,lichenified plaques.
DISTRIBUTION Especially on the antecubital and popliteal fossae, wrists. May resolve at his stage or continue to adulthood.
ADULT-TYPE ATOPIC DERMATITIS:
May evolve per se or arise from childhood AD.
Skin Lesions: Itching is severe & paroxysmal, scaling, dryness, lichenification± fissuring.
Distribution of Lesions: Predilection for the flexures, front and sides of the neck, eyelids, forehead, face, wrists, and dorsa of the feet and hands, or generalized.
Besnier's prurigo:This is a term used to describe a predominantly excoriated (scratched) skin in atopic eczema.
Complications of AD.:
1-Overriding bacterial infections like s.aureus infection leads to extensive erosions and crustations.
2- Severe viral infections: for eg. Herpes simplex when affect atopic person leads to (eczema herpeticum): widespread infection with the herpes simplex along the area of atopic D.
3-Poor growth ( because itching disturbs sleeping & growth hormone release occurs mainly during deep sleep. In addition to the effects of steroid Rx)
4- Local & systemic SE. of steroids.
5-Negative psychological effects.
Investigations:
1-CBP. Shows eosinophilia.
2-Total IgE: Increased IgE in serum.
3-Radioallergosorbent Testing (RAST): detects specific IgE for causative allergen.
Differential diagnosis:
1-scabies. 2- Xerosis
systemic causes of itching.
dermatitis herpitiformis.
allergic contact dermatitis.
Treatment: is the same, in addition avoid irritants, avoid scrupulous bathing that exacerbate dryness, &frequently use emollients.
Seborrhoeic Dermatitis
Definition: Seborrheic dermatitis (SD) is a type of endogenous eczema characterized by redness and scaling. Occurring in regions where the sebaceous glands are most active.
Pathophysiology: Pityrosporum ovale (acomensal fungus) is said to play a role in the pathogenesis.
Age: Infancy (within the first months), & after puberty.
Sex More common in males.
Symptoms: Pruritus is variable.
Skin Lesions: Yellowish greasy scaling errythematous, patches of varying size, rather sharply marginated.
Mild scalp SD causes flaking, i.e., dandruff (or white dry scaling: pityriasis sicca).
Fissures are common when external ear, axillae, groin, and submammary areas are involved (weeping).
Distribution:Seborrhoic area encludes: Scalp, eyebrows, eyelashes (blepharitis), glabella, nasolabial folds, , retroauricular area, auditory meatus, over the sternum, submammary areas, axillae, umbilicus, groins, anogenital area. Any of these sites could be involved
Seborrhoeic eczema of infancy
A common short-lived non-pruritic inflammatory disorder of the first few weeks of life affecting especially the scalp, face, axillae and napkin area. In its simplest and commonest form, it commences in the scalp as yellow thick sticky crusts, surrounded by erythema Scalp involvement in infants is called “Cradle cap”. The napkin area is often affected but the eczema spreads beyond the location covered by the napkin onto. The patches are red, scaly and ill-defined.
Differential Diagnosis:
Psoriasis vulgaris.
dermatophytosis (tinea capitis, tinea faciale, tinea corporis),
candidiasis (intertriginous).
Tenia amiantacea.
Napkin dermatitis.
Diagnosis:Usually made on clinical findings
TREATMENT:
A-general measures:
Regular bathing to decease sebrohoea
Avoid irritant & oily applications.
B-Topical Therapy:
1-FOR scalp effective shampoos containing 2 % ketoconazole, shampoo, used initially to treat and subsequently to control the symptoms; lather can be used on face and chest during shower. Ketoconazole cream for the body.
2-Corticosteroids for more severe cases; hydrocortisone or low-potency fluorinated corticosteroid solution, lotion, or gel ( for scalp) following a medicated shampoo. 1 % or 2.5% hydrocortisone cream for other sites.
* Treatment of seborrhoeic eczema of infancy is emollients & if needed mild topical steroids.
Discoid eczema (Nummular Eczema)
Nummular eczema is a chronic, intensely pruritic, coin-shaped erythematous scaly plaques, especially common on the lower legs during winter months; often seen in atopic individuals.
Age: Two peaks in incidence: young adults and old age.
Skin Lesions: Plaques may become exudative and crust( wet type). Or dry scaly plaques (Dry type).
DISTRIBUTION: Sites of Predilection Lower legs (older men), trunk, hands and fingers (younger) or generalized.
Pathophysiology: Unknown.
Course and Prognosis: Chronic. Often difficult to control even with potent topical corticosteroid Preparations.
Differential diagnosis: 1-tinea, 2-DLE., 3-Psoriasis.4-contact dermatitis.
Diagnosis: clinical, biopsy - rarely required, shows eczema.
Treatment: (same)
Pompholyx (dyshidrotic eczema)
Definition: A pruritic, episodic, sometimes chronic vesicular eruption of the palmar (Cheiropompholyx) (80 %) or plantar ( Podopompholyx) surfaces.
Age: Majority under 40 years (range 12 to 40 years).
Sex: Equal ratio.
Lesions: very itchy deep seated tiny vesicles which may coalesce and become bullae affecting the skin of the sides of the fingers and palms,and sides toes, and soles which weep and then dry and become painful dry, hyperkeratotic and fissured.
Differential diagnosis: contact dermatitis.
Diagnosis: clinical, biopsy - rarely required, shows eczema.
Treatment: (same)
Lichen simplex chonicus (neurodermatitis).
Definition: A pruritic eczematous condition resulting from continued rubbing and scratching at a localized area of the skin and often associated with a period of anxiety. The constant scratching leads to a vicious cycle of itchscratchrelease of histamineitch
Age: Over 20 years.
Sex: More frequent in women.
Lesion: Characteristicly itchy well defined a solitary unilateral plaque erythematous or hyper pigmented with lichenified surface. itching is paroxysmal. And it becomes a pleasure to scratch. Often the rubbing becomes, reflexive and a subconscious habit. Lightly stroking the involved skin with a cotton swab generates a strong desire to scratch the skin; the same reflex is not present in uninvolved skin.
Distribution: anywhere but especially: back of neck (in female), lower leg (in males) just below elbow, hands, genitalia, buttock,(in both).
Diagnosis: clinical, biopsy - rarely required, shows eczema.
Differential diagnosis: hypertrophic lichen planus.
Treatment: (same) Relieve anxiety, stop scratching super potent topical steroids under occlusion.
Varicose (stasis) eczema
Definition: An inflammatory disorder of the skin of the lower legs associated with venous hypertension.
Lesion: an itchy ill-defined, erythematous patches with fine scaling, sometimes with excoriations, on lower legs, especially around varicosities and venous ulcerations.
Complications:
1- contact dermatitis from medicaments,
2- infection.
3-Inverted champagne bottle look to the leg may result from prolong disease and fibrosis.
Ulceration.
Diagnosis: clinical.
Treatment: Rxof venous insufficiency, + Rx. Of eczema.
Asteatotic Dermatitis
occurs in winter and in older persons with dry skin due to decreased sebaceous glands activity. mainly affecting the legs, but may affect arms, and hands or the trunk. The eruption is characterized by itchy, eyhematous dry, scaling “cracked,” fissured skin. often called (eczema craquelatum), eruption exacerbates by frequent bathing in hot soapy baths or showers.
Rx.: Avoiding over bathing with soap, using water baths containing bath oils followed by immediate liberal application of emollient ointments. Mild to medium-potency corticosteriod ointments applied twice daily until the eczematous component has resolved.
Pityiasis alba
Very common condition especially among atopic individuals usually affect adolescents & children most commonly on the face in form of mild erythema followed by appearance of hypopignmented patch with powdery scales may be associated with intestinal helmenths.DDx.:vitiligo, tinea versicolor,leposy,postinflammatory hypopigmentation.
Rx.:Dx&Rx. intestinal helmenths, avoid excessive sun exposure, lubricant± mild topical corticosteroid.