Lecture 8: Eczema Flashcards
Other than Atopic Eczema, what are the main types?
Exogenous Causes:
- Contact Dermititis
- Lichen Simplex
- Photoallergic Eczema
Endogenous Causes:
- Discoid
- Venous
- Seborhoeaic
- Pompholyx
- Juvenile Plantar Dematitis
How would you spot photoallergic eczema?
It shows a distribution around light exposed areas
I.e. Face, Sleeve lines, neck line etc.
Explain how Contact Dermatitis works
Comes in 2 Forms:
- Allergic (Type 4 hypersensitivity reaction)
- Irritant (Friction, cold, long water exposure or chemicals e.g. detergent)
What occupations get a lot of contact dermatitis?
- Hairdressers (lots of washing & water)
- NHS staff (Constantly washing hands)
- Cleaners (Detergents and acids)
- Babies (not an occupation, but get a lot of contact nappy rash)
Explain what discoid eczema is?
Circular plaques of eczema. Mainly at sites of irritation
If you find eczema on an infants scalp, proximal flexures and trunk what do you think it is?
Seborrhoeic Eczema
Because it targets areas where there’s lots of sebaescous glands like the scalp, armpits and chest
So what causes Seborrhoeic Eczema and how do you treat it?
Usually a Malassezia Yeast infection
Topical Ketoconazole
You might get more patients during the winter months coming in with very dry skin thats cracked an scaly, mostly on thier shins. Why is that?
They have asteatotic eczema.
It occurs when the skin becomes very dry such as:
- In hot climates
- Excessive soap washing
- Cold months (people spend a lot of time indoors with dry heating)
A patient presents with intensely itchy sudden crops of vesicles appearing on their hands and feet along with redness and flaking?
Probably Pompholyx (aka vesicular dermatitis) A form of eczema involving formation of blisters on the hands/feet
Explain how venous eczema occurs?
Increased venous pressure (mostly legs)
Causes oedema
Body reacts to oedema triggering eczema
So it presents with the classic red, flaky, itchy eczema. Possibly plus:
- Varicose Veins
- Brown/red discolouration
- Swelling
- Pain
- Hardened/tight skin (lipodermatosclerosis)
- White “scars” (atrophie blanche)
Finally what happens if a patient with eczema gets a disseminated HSV infection?
Eczema Herpeticum!
How does Eczema Herpeticum present?
Painful eczema getting rapidly worse
Clusters of blisters and ‘punched-out’ erosions
Fever, lethargy and malaise
How would we treat venous eczema?
Other than standard eczema treatments:
compression stocking - Reduce the oedema, reduce the reaction
How would we treat Eczema Herpeticum?
Antiviral Aciclovir to clear the HSV
Mild topical steroid (e.g. hydrocortisone) to lessen the eczema
Get an ophthalmology consult if there’s periocular disease
A chronic inflammatory T-Cell mediated condition of the skin in response to environmental allergensIts very common
Define Atopic Eczema?
Spongiosis - Intercellular Oedema Acanthosis - Thicking of Epidermis Inflammation
What are the parts of eczema pathology?
Flexures Neck Face Eyelids Hands & Feet
What are the common places to find atopic eczema?
StressCold or HeatAllergens e.g. pollen
What can trigger/worsen atopic eczema?
Red, scaly patches sometimes with papules, vesicles, exudate and crusting/It itches
How does Eczema present?
Lichenification - Leathering Fissures Large plaque lesions
what does chronic eczema lead to?
- Topical Steroids- Systemic Immunosuppression- Education (Causative/exacerbating factors)- Emollients/Soap susbstitutes- Anti-histamines- Anti-microbials- UV light
Quick overview of the main eczema treatments:
Some patients with eczema can contract infections through the damaged skin
When are anti-microbials necessary for eczema?
They serve to diminish the inflammation & Itching
How do anti-histamines help eczema?
Hydrocortisone - low potency Betamethasone - High potency
What topical steroids could be used for Eczema?
Azithioprine Ciclosporin Methotrexate Calcineurin inhibitors e.g. Tacrolimus
What re the types of systemic immunosuppression for Eczema
They inhibit calcineurina protein involved in T cell activation. Since T cells mediate Atopic eczema they serve to inhibit the whole disease
How do calcineurin inhibitors work?
Many are involved but the Filaggrin gene is the primary one
Main gene involved in atopic eczema?
