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Eczematous Diseases << back to index
definition From Greek, meaning the result of (-ma) boiling (-ze) out or over (ec-). [Leider] A clinical process that is clearly superficial in form and that, early, is erythematous, papulovesicular, oozing, and crusting and, later red-purple, scaly, lichenified and possibly pigmented. [Leider]

In addition, eczema is characterized histologically by epidermal changes of intracellular edema, spongiosis, or vesiculation. [Leider]

stages
  • acute stage
    • erythema, papules, vesicles,
    • oozing, +/- crust
    • distinct margins
  • histology
    • epidermal edema
    • ballooning and spongiosis or vesiculation
    • (inflammatory infiltrate)
  • transitional stage
    • erythema, scale
    • indistinct margins
  • chronic stage
    • scale, minimal erythema
    • indistinct margins
    • lichenification
infectious eczema non-infectious eczema
viral
· herpes simplex
· varicella zoster
contact dermatitis
allergic and irritant
atopic dermatitis
fungal
· T. mentagrophytes
nummular dermatitis
dyshidrosis
bacterial
· superficial pyodermas
stasis dermatitis
xerotic eczema

Non-Infectious Eczema

Irritant Contact
DermatitisMechanism: direct injury of the skin from acute or chronic application of various substances.
Presentation: erythema, edema and occasionally vesicles (early), scale, lichenification (late). Treatment: avoidance of offending substance, supportive care.

Allergic Contact Dermatitis
Mechanism: cell-mediated immunity to applied antigen leads to inflammatory response which may include vesicles.
Presentation: erythematous and edematous (spongiotic) or vesicular skin in the pattern of contact.
Treatment: avoidance of the offending substance, supportive measures.

 
common allergens
poison oak
nickel
rubber
chromate
paraphenylene diamine
dermatitis medicamentosa

poison oak
Presentation: acute pruritic dermatitis with linear grouping of vesicles
Confirmation: history of possible exposure
Treatment: remove urushiol from skin, clothing, and objects, apply drying measures, administer corticosteroids


Poison Oak Dermatitis

nickel dermatitis
Presentation: dermatitis in contact areas for jewelry or metal clothing fasteners
Confirmation: skin patch testing
Treatment: topical corticosteroids, avoid further exposure

rubber dermatitis
Presentation: dermatitis at site of exposureŠ shoes (adhesive), elastic in clothing, surgical gloves, etc.
Confirmation: patch test to accelerators and antioxidants, possible RAST test for latex
Treatment: use topical corticosteroids, avoid further exposure to the allergen


Mercaptobenzothiazole reaction

Atopic Dermatitis
Definition:the itch that rashesA chronically relapsing eczematous dermatitis characterized by pruritus and a typical morphology and distribution according to the stage of the disease.


Infantile atopic dermatitis

Mechanisms: putative defect in cell mediated immunity.
Presentation:

  • infantile:
    • onset from birth to two years
    • pruritus
    • erythema and scaling of cheeks, sparing of perioral, perinasal areas
    • may involve flexors and extensors
  • childhood and adult phase
    • evolving in early childhood
    • pruritus
    • erythema, scale, lichenification
    • antecubital and popliteal fossae
    • neck, eyelids, postauricular, wrists
    • may become generalized

Treatment: moisturizers, topical corticosteroids, oral antibiotics.

Complications

  • viral infections
  • fungal infections
  • bacterial infections

Nummular Dermatitis
Mechanisms: unknown
Presentation: intense pruritus of coin-shaped erythematous and edematous plaques.
Treatment: potent topical corticosteroids.

Dyshidrosis
Mechanisms: unknown, except for the ³id reaction²
Presentation: vesicles with or without erythema involving the palms and sides of the fingers, may involve soles and toes
Treatment: use potent topical corticosteroids, avoid stress.

Stasis Dermatitis
Mechanism: increased venous pressure, slowed microcirculation, margination of white blood cells.
Presentation: distal leg involved with edema and erythema, later hyperpigmentation and sclerosis.
Treatment: alleviate edema, use support hose, topical steroids, emollients.Complications


  • edema
  • infection
  • ulceration



Venous stasis dermatitis and ulcer

Dermatitis of Xerosis
Mechanisms: defatted skin from soap and water, worse with age; irritation from chlorine
Presentation: background of dry scaly skin; red plaques with thin superficial fissures
Treatment: topical corticosteroid ointments, emollients, avoidance of soap and irritants

Eczema Diagnosis by Location and Morphology

Dorsum of hands
round plaques = nummular eczema
general or other pattern = contact
Palmar surface
dyshidrosis
id reaction
general involvement
flexural dermatitis = atopic
round plaques = nummular
patterned dermatitis = contact
lower extremity
distal leg with varicosity = stasis dermatitis
mid to upper leg with dry skin, fissured erythematous plaques = xerotic eczema
round plaques = nummular
contact pattern = contact