Dermatitis infections

Question 1

Other than Atopic Eczema, what are the main types?

Answer 1

Exogenous Causes:

• Contact Dermititis
• Lichen Simplex
• Photoallergic Eczema

Endogenous Causes:

• Discoid
• Venous
• Seborhoeaic
• Pompholyx
• Juvenile Plantar Dematitis

Question 2

How would you spot photoallergic eczema?

Answer 2

It shows a distribution around light exposed areas

I.e. Face, Sleeve lines, neck line etc.

Question 3

Explain the difference between allergic contact and irritant contact dermatitis [5]

Answer 3

Comes in 2 Forms:

• Allergict contac (Type 4 hypersensitivity reaction)
• Irritant contact (Friction, cold, long water exposure or chemicals e.g. detergent)

Question 4

What groups of people get a lot of contact dermatitis? [4]

Think occupational

Answer 4

• 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)

Question 5

Discoid eczema: presentation [1]

Answer 5

Circular or annular itchy patches

Question 6

If you find eczema on an infants scalp, proximal flexures and trunk what is the likely diagnosis? [2]

Answer 6

Seborrhoeic Eczema

Because it targets areas where there’s lots of sebaceous glands like the scalp, armpits and chest

Question 7

So what causes Seborrhoeic Eczema and how do you treat it? [5]

Answer 7

Usually a Malassezia Yeast infection

Topical Ketoconazole
TAR shampoo
Antifungal shampoos
Mild topical steroids

Question 8

You might get more patients during the winter months coming in with very dry skin thats cracked an scaly, mostly on thier shins. What is the likely diagnosis?
Name 2 other environmental factors that can precipitate this condition

Answer 8

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)

Question 9

A patient presents with intensely itchy sudden crops of vesicles appearing on their hands and feet along with redness and flaking?

Answer 9

Probably Pompholyx (aka vesicular dermatitis)
A form of eczema involving formation of blisters on the hands/feet

Question 10

Explain how venous eczema occurs? [3]

Presentation [6]

Answer 10

Increased venous pressure (mostly legs)
Causes oedema
Body reacts to oedema triggering eczema

So it presents with the classic red, flaky, itchy eczema. Associated symptoms:

• Varicose Veins
• Brown/red discolouration
• Swelling
• Pain
• Hardened/tight skin (lipodermatosclerosis)
• White “scars” (atrophie blanche)

Question 11

Finally what happens if a patient with eczema gets a disseminated HSV infection?

Answer 11

Eczema Herpeticum!

Question 12

How does Eczema Herpeticum present? [3]

Answer 12

Painful eczema getting rapidly worse
Clusters of blisters and ‘punched-out’ erosions
Fever, lethargy and malaise

Question 13

How would we treat venous eczema? [3]

Answer 13

Other than standard eczema treatments:

Compression stocking - Reduce the oedema, reduce the reaction

Question 14

How would we treat Eczema Herpeticum? [3]

Answer 14

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

Question 15

Signs of dermatitis on examination

Answer 15

Acute paronychia, ridging of the nails, onycholysis.