Dermatology: Eczematous Eruptions

Question 1

What is atopic dermatitis ?

Answer 1

It is an IgE mediated type 01 HSR which is part of the allergic triad, also known as atopic march consist of Asthma, Allergic rhinitis and atopic eczema.

Question 2

What are the goals of therapy in atopic dermatitis ?

Answer 2

To relive symptoms and delay time b/w flare ups.

Question 3

What are the most common treatments for atopic dermatitis ?

Answer 3

Emollients and topical steroids

Question 4

What is the pathogenesis of atopic dermatitis ?

Answer 4

*Genetic defects causing disruption of skin barrier function.
* Skin hypersensitivity to irritants
* Dermal immune cells interacts with environmental antigens leading to immune mediated response characteristic of dermatitis.

Question 5

What is the prevalence of atopic dermatitis in Ireland ?

Answer 5

1 in 5 children and 1 in 10 adults. all cases start in the first decade of life and many are undiagnosed.

Question 6

What are the lesion locations of atopic dermatitis by age

Answer 6

In infants: Face, extensor surface of the limbs and trunk with sparing of diaper area.
In younger children: Flexer folds are affected more.
In adults: Licenification and excoriated plaques at hands, feet, ankle, wrist, flexer surfaces, perioral and periorbital areas as well as neck.

Question 7

What is the clinical presentation of the acute atopic dermatitis ?

Answer 7

The lesions are weeping and crusting vesicles.

Question 8

What is the clinical presentation of the subacute atopic dermatitis ?

Answer 8

Erythematous dry scaly lesions with papules and plaques.

Question 9

What is the clinical presentation of the chronic atopic dermatitis ?

Answer 9

Lichenified lesions with a combination hyperpigmentation and hypopigmentation due to repeated excoriation.

Question 9

What is the UK working party diagnostic criteria for atopic dermatitis ?

Answer 9

It is mainly a clinical diagnosis

Itchy skin + 3 OF THE FOLLOWING:
* History of asthma or allergic rhinitis
* History of flexural involvement
* History of generalized dry skin
* Onset of rash before two years of age
* Visible flexural dermatitis

Question 9

what is the first line treatment for atopic dermatitis with persistent lesions on face, neck, axilla, groin, flexor surfaces?

Answer 9

Low potency steroids(Grade V - VII) such as Betamethasone valerate cream (0.1%), Desonide cream (0.05%), Hydrocortisone acetate cream (1%).

Question 10

What is the treatment for atopic dermatitis flare ups

Answer 10

Moderate potency topical cortico steroids (Grade III - V) such as Amcinonide ointment (0.1%), Amcinonide ointment (0.1%), and Betamethasone valerate cream (0.1%).

Question 11

What is the treatment for chronic atopic dermatitis with
lichenified plaques ?

Answer 11

High potency (Grade I - III) such as Clobetasol propionate cream (0.05%) or Betamethasone dipropionate ointment (0.05%). Must avoid sun expouser to treated areas to prevent steroids induced skin atrophy and telangectasias of the face.

Question 12

What is the treatment of atopic dermatitis striae ?

Answer 12

Topical steroids depending on the severity the potency varies.

Question 13

What is the second line management of moderate to severe atopic dermatitis ?

Answer 13

Topical Calcineurin Inhibitors such as Tacrolimus or Pimecrolimus. Reserved for patients > 2 year old.

Question 14

What is the advantage of Topical calcineurin inhibitors ?

Answer 14

No skin atrophy

Question 15

What is the danger of Topical calineuin inhibitors ?

Answer 15

lymphomas and skin malignancies.

Question 16

What is the Tx of severe refractory
atopic dermatitis disease?

Answer 16

*Referral to specialist
* Immunosuppressants (ciclosporine, azathioprine)
* Monoclonal Antibody (dupilumab (Dupixent®))
* Tyrosine Kinase (JAK1 and JAK2) Inhibitors (baricitinib (Olumiant®))
* Phototherapy

Question 17

What is an irritant contact dermatitis ?

Answer 17

It is a nonspecific immune response that causes Localized
inflammatory skin
response to irritant such as Water,Detergents and
surfactants, Solvents, Oxidizing agents.

Question 18

What is the clinical presentation of the acute irritant contact dermatitis ?

Answer 18

It is a decrescendo phenomenon presenting with painful stinging or burning edematous and erythematous vesicles, bullae, epidermal necrosis.

Question 19

What is the chronic presentation of Irritant contact dermatitis ?

Answer 19

Erythema and dryness progressing to hyperkeratosis, fissuring and lichenification.

Question 20

When should patch test needs to be done in contact dermatitis ?

Answer 20

When the diagnosis is doubtful as to whether it is allergic or contact dermatitis.

Question 21

What is the treatment for irritant contact dermatitis ?

Answer 21

Remove expouser to irritants and topical steroids until symptoms resolve.

Question 22

What is the pathogenesis of allergic contact dermatitis ?

Answer 22

Exposure to an allergen sensitises the immune system to the allergen. When a second exposure to the same allergen occurs it mounts a T cell mediated type 04 hypersensitivity reaction which is called allergic contact dermatitis.

Question 23

What is the clinical presentation of allergic contact dermatitis ?

Answer 23

It presents as erythematous indurated plaques with or without vesicles, Bulla or edema.

Question 24

What is the diagnostic work up to allergic dermatitis ?

Answer 24

Skin patch testing.

Question 25

What are the treatments for allergic contact dermatitis ?

Answer 25

• Avoidance of offending allergen
• Topical steroids
• Topical calcineurin inhibitors (e.g., tacrolimus)
• Oral steroids
• Phototherapy

Question 26

What are the differences between ICD vs ACD

Answer 26

*acute onset in ICD. Whereas, Variable onset in ACD because immune sensitisation to the allergen is a must.

• ICD symptoms progress in a decrescendo fashion. Whereas ACD symptoms progress in a crescendo fashion.
• Ulcerations may occur in ICD. Whereas ulcerations or skin necrosis are rare in acute ACD.
• ICD will have sharply demarcated rashes in areas of contact. Whereas in ACD lesions have ill defined bounderies.
• In ICD the lesions are painful. whereas in ACD the lesions are pruritic.

Question 27

What is the cause of seoborrhic dermatitis ?

Answer 27

The exact cause is unknown, M. Furfur may play a role in the pathogenensis.

Question 28

What is the clinical presentation of seborrhic dermatitis?

Answer 28

It has a biphasic presentation seen in infants and adults. The lesions are wll demarcated erythematous geesy looking Yellowish scales. They get worse with stress, cold and dry winter.

Question 29

What is the management of seborrhic dermatitis?

Answer 29

ketoconazole shampoo, selenium sulfide, zinc pyrithione 1%, salacylic acid+coal tar. Topical anti-fungals (e.g., ketoconazole) or Topical corticosteroids or Topical calcineurin inhibitors.

Question 30

What is Nappy rash

Answer 30

It is form of ICD due to Overhydration of skin, maceration, Elevation of skin pH and Colonization of bacteria and candida due to wet nappy use.

Question 31

What is the management of nappy rash?

Answer 31

Switch to disposable nappies or add nappy
liners to cloth nappies
* Wash with mild soap and water then allow to
air dry
* Apply emollient ointment containing
petrolatum and zinc oxide
* Topical steroids if above does not work
* Topical antifungal if suspicious for candida

Question 32

What is perioral dermatitis ?

Answer 32

It is an ideopathic condition some are associated to topical or inhaled steroid use.

Question 33

What is the clinical presentation of perioral dermatitis ?

Answer 33

Small itchy red tender papules which spares skin bordernig the lips, eyelids and nostrils. The overlaying skin is usually dry and flakey.

Question 34

What is the treatment for perioral dermatitis ?

Answer 34

*Discontinue all potential triggers
* Switch to non-soap cleanser
* Can use short course of topical antiinflammatory antibiotics (clindamycin,
metronidazole)
* Reintroduce topical steroids (if previously
used) with careful application

Question 35

What is Nummular eczema ?

Answer 35

It is an ideopathic condition presents with Pruritic, round, coin-shaped patches on upper and lower extremities.

Question 36

what is the course of Nummular eczema ?

Answer 36

Initially: Dull red, exudative, and crusting
* Over time: Dry, scaly, central clearing
* Recurrent, chronic-relapsing

Question 37

What is the management of Nummular eczema ?

Answer 37

General measures
* Topical steroids +/- occlusive dressing
* Intralesional corticosteroid injection
(triamcinolone)