Dermatitis

Types of eczema:
Endogeneous Eczema:
  •  Atopic dermatitis
  • Seborrhoeic dermatitis
  • Nummular eczema
  • Pompholyx (Dyshidrotic eczema)
  • Asteatotic eczema
  • Stasis dermatitis
  • Juvenile plantar dermatitis
  • Lichen simplex chronicus
Exogenous Eczema:
  • Irritant contact dermatitis
  • Allergic contact dermatitis
  • Photodermatitis
  • Infectious eczematoid dermatitis.
ATOPIC DERMATITIS
  • Synonyms: Neurodermatitis, Besnier's prurigo, Infantile eczema
  • Positive family history of allergic rhinitis, asthma or eczema
  • Pruritis is the most common symptom
  • Course marked by exacerbations and remissions
  • Clinical course lasting longer than 6 weeks
  • Lichenification of skin
  • Infantile pattern: involves face, neck, extensor surfaces and groin.
  • Childhood and adolescent pattern: involves flexural skin, particularly in the antecubital fossa and popliteal
  • fossa.
  • Cutaneous stigmata of AD
  • Perioral pallor
  • Extra fold of skin beneath the lower eyelid (Dennie-Morgan folds)
  • Increased palmar skin markings
  • Increased incidence of cutaneous infections, particularly Staphylococcus aureus
  • Diagnosis: clinically - dry skin, severe itching, flexural lichenification, hand eczema, nipple eczerr and eyelid
  • eczema in adults, history of atopy in the family/patient, and raised IgE serum levels.
CONTACT DERMATITIS
  • Irritant contact dermatitis
  • Synonyms: Occupational dermatitis, Housewive's eczema
  • Materials may injure by direct toxic action (irritants)
  • Due to contact with irritants like detergents, acids, alkaline chemicals, oils, organic solvents etc
  • Housewife's eczema, diaper dermatitis and industrial dermatitis are examples of cumulative irritant contact
  • dermatitis.
  • Most common site affected is hand.
  • Most common cause of contact dermatitis in Indian women – detergent.
  • Allergic contact dermatitis
  • May induce immunological reaction of delayed hypersensitivity type (allergens) – Allergic contact dermatitis
  • Most common metal causing contact dermatitis is nickel.
  • Most common cause of air-borne contact dermatitis– parthenium.
  • Barloque dermatitis due to cosmetics.
Diagnosis:
  • Patch test.
  • Skin hypersensitivity test (delayed type).
  • Readings are made after 48 hours.
  • Seborrheic Dermatitis
  • Most common in infants and very young. Most common location is the scalp.
  • Greasy scales overlying erythematous patches or plaques
  • Scaling of the external auditory canal is common
  • In the first week of life, it typically occurs in the scalp ("cradle cap"), face, or groin
  • In adults, it is seen in patients with Parkinson's disease, CVA and HIV infection
  • Leser-Trelat sign: Sudden eruption of multiple seborrheic keratosis lesions in associated internal malignancy
Exam Question
  • Parthenium causes allergic contact dermatitis through air.
  • Most common cause of plant induced dermatitis in India is Parthenium.
  • A 3 year old child has eczematous dermatitis on extensor surfaces. His mother has a history of Bronchial asthma. Diagnosis should be Atopic Dermatitis.
  • Commonest site of Atopic dermatitis is Elbow( Antecubital fossa).
  • Dennie -Morgan fold ,Hertoghe’s sign ,Hyperlinearity of palms are features of Atopic Dermatitis.
  • Facial pallor ,Pityriasis alba , Keratosis pilaris are skin findings in Atopic Dermatitis.
  • Langerhan cell histiocytosis produce a seborrheic dermatitis like lesions in an infant.
  • Air-borne contact dermatitis can be diagnosed using Patch test.
  • 36 year old farmer presented to dermatology department with pruritic erythematous lesions on arms, forearms, face and retroauricular area after removal of weeds in his farm. A diagnosis of phytodermatitis was made. Parthenium Hyterophus is the most likely plant responsible for this condition.
  • A child presents with seborrheic dermatitis, lytic skull lesions, ear discharge and hepatosplenomegaly; likely diagnosis is Histiocytosis X.
  • Contact dermatitis is a type IV hypersensitivity.
  • In contact dermatitis T cells play major role.
  • Doxycycline has maximum propensity for photodermatitis.
  • Baby with recurrent infection of ear & discharge & seborrheic dermatitis with hepatosplenomegaly with cystic skull lesions. Diagnosis is Langerhan's Cell Histiocytosis. Minor clinical feature in diagnosis of atopic dermatitis are Dry skin, Morgagnian fold, Pitriasis alba.
  • Most common precipitant of contact dermatitis is Nickle.
  • Exfoliative dermatitis is seen in : Pityriasis rubra pilaris , Psoriasis , Drug hypersensitivity.
  • Gold poisioning leading to exfoliative dermatitis is treated by Steroid.
  • Most common cause of allergic contact dermatitis in Indian female is Detergents.
  • Berloque dermatitis is due to contact with cosmetics.
  • Photosensitive dermatitis are Psoriasis ,Pellagra , Pemphigus.
  • Atopic dermatitis may be associated with Conjunctivitis,Keratoconus , Cataract.
  • Dennies Morgan fold is indicative of Atopic Dermatitis.
  • The day after playing in the high grasses of a neighbour's fields, this boy develops an erythematous, and itchy rash on his arms, legs, and neck.Spongiotic Dermatitis best describes this inflammatory condition.
  • RAST test is used in diagnosis of Allergic Dermatitis.
  • Hanifin & Rajke is the diagnostic criteria for Atopic Dermatitis.
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