Paediatric Dermatology Flashcards
what is eczema?
this is an itchy, dry inflammatory skin disease
classification of eczema
endogenous
exogenous
endogenous types of eczema
- Atopic – genetic barrier dysfunction
- Seborrheoic – face/scalp – scale associated
- Discoid – annular/circular patches
- Pomphylx – vesicles affecting palms/soles
- Varicose – oedema/venous insufficiency
exogenous types of eczema
- Allergic contact dermatitis –sensitised to allergen
- Irritant contact dermatitis – friction, cold, chemicals e.g. acid, alkalis, detergents, solvents
- Photosensitive/photoaggravated eczema
childhood eczema flares can be associated with
- Infections/viral illness
- Environment: central heating, cold air
- Pets: if sensitised/allergic
- Teething
- Stress
- Sometimes no cause for flare found
what is atopy?
This is the commonest type of eczema, particularly in children. Atopy is an overactive immune
response to environmental stimuli. Immune mediated defects in the skin barrier function – dry
inflamed skin. Atopic tendency is a tendency to 3 commonly linked conditions – asthma, eczema and
hayfever. Usually 1 or more family members are affected. Can have only 1, 2 or all 3. In infancy atopic
eczema typically starts on the face/neck (cheeks common), and can spread more generally. In older
children flexural pattern predominates (antecubital fossae, popliteal fossae, wrists, hands, ankles).
Facial eczema also possible and can recur.
what is the defect in atopic eczema? what does this result in?
Inherited abnormalities in the skin – the skin “barrier defect”. Abnormality in filaggrin expression.
Filaggrin proteins bind the keratin filaments together. They also play a role in producing a natural
moisturising factor.
Loss of skin barrier functions:
1. Loss of water
2. Irritants may penetrate (soap, detergent, solvents, dirt)
3. Allergens may penetrate (pollens, dust-mite, antigens, microbes)
seborrheoic dermatitis: where
scalp
face
seborrheoic dermatitis: who
babies under 3 months, usually resolve within 12 months
seborrheoic dermatitis: associated with
proliferation of various species of the skin commensal malassezia in its yeast form
cradle cap
seborrheoic dermatitis: treatment
emollients
antifungal creams
antifungal shampoos
mild topical steroids
discoid eczema
form of scattered annular/circular patches of itchy eczema
where does pomphylx eczema affect?
hand and foot
varicose eczema: associated with
oedema
varicose veins
chronic leg swelling
varicose eczema: symptoms
dry
inflammed
ulceration
varicose eczema: treatment
emollients
topical steroids
compression stockings
allergic eczema
become sensitised to allergen, patch testing helpful.
irritant eczema
repeated contact; water and soaps, touching irritant foods; citrus, tomatoes, chemical irritants.
when to suspect food allergies?
• Immediate reactions (lip swelling, facial redness/itching, anaphylactoid symptoms)
o Late reactions (worsening of eczema 24/48 hours after ingestion) – especially if
pattern with specific food (food diaries encouraged).
o GI problems
o Failure to thrive
o Severe eczema unresponsive to treatment
o Severe generalised itching – even when the skin appears clear
how to test food allergy
blood test for specific IgE antibodies to certain foods
skin prick testing
commonest food allergies causing skin reactions
Milk/dairy, soy, peanuts, eggs, wheat, fish
airborne pathogens causing skin reactions
House dust mite, pet dander, pollens
treatment of eczema
- Emollients (Lotions, creams or ointments – fragrance free, greasier ointments more effective)
- Topical steroids
- Calcineurin inhibitors (e.g. protopic – steroid sparing topical agents)
- UVB light therapy
- Immunosuppressive medication
very potent topical steroid
dermovate
potent topical steroid
betnovate
moderate topical steroid
eumovate
mild topical steroid
hydrocortisone
how to use topical steroid
Once daily for 1-2 weeks
o If improvement then use alternate days for a few more days
o Then if stubborn/persistent areas can use twice weekly in these areas
o If at any point the eczema starts flaring, go back to daily applications
impetigo
Impetigo is a common acute superficial bacterial skin infection. Pustules and honey-coloured crusted
erosions develop as a result of staph aureus. Topical antibacterial (Fucidin) and oral antibiotic
(flucloacillin).
molluscum contagiosum
This is a common benign self-limiting condition caused by the molluscipox virus. It has a 2 week to 6
month incubation. Transmission is by close, direct contact. It looks like pearly papules with umbilicated
centre. It can take 24 months to clear. Treatment is reassurance and 5% potassium hydroxide.
viral warts
These are often skin coloured. Common non-cancerous growths of the skin caused by infection with
HPV. If found on the sole of the foot they are called verrucas. Transmitted by direct skin contact.
Stimulate the person’s own immune system to respond. Cryotherapy and topical paints (salicylic acid)
can help. 90% resolve in 24 months.
viral exanthens
These are common and associated with a viral illness. Symptoms include fever, malaise and headache.
Either a reaction to a toxin produced by the organism, damage to the skin by the organism or an
immune response.
• Chicken pox
• Measles
• Rubella
• Roseola (herpes virus 6)
• Erythema infectiosum (parvovirus B19, slapped cheek
chicken pox
Chicken pox is a highly contagious disease caused by primary infection with the VZV. One infection is
thought to confer lifelong immunity. Immunocompromised individuals are susceptible to the virus at
all times. Red papules (small bumps) progressing to vesicles (blisters) often start on the trunk. Itchy
and associated with viral symptoms.
The virus has an incubation period of 10-21 days. It is contagious 1-2 days before the rash appears and
until the lesions have crusted. It is self-limiting. Rarely associated with pneumonia and encephalitis.
parvovirus - slapped cheek
• Fifth disease/erythema infectiosum
• Incubation 7-10 days.
• Viral symptoms.
• Erythematous rash cheeks initially and then also lace like network rash (trunk and limbs). Can
take 6w to full fade.
• Usually a mild self-limiting illness
• Virus targets red cells in bone marrow.
• Very rarely
o Aplastic crisis (if haemolytic disorders)
o Risk to pregnant women (spontaneous abortion, intrauterine death, hydrops fetalis)
hand, foot and mouth disease
- Enterovirus.
- Usually Coxsackie virus A16
- (can also be due to Enterovirus 71 and other coxsackievirus types)
- Blisters on the hands, feet and in the mouth. Viral symptoms.
- Epidemics late summer or autumn months.
- Self-limiting, treatment supportive.
erythema nodosum: clinical features
• Painful, erythematous subcutaneous nodules
• Over Shins; sometimes other sites
• Slow resolution - like bruise
6-8 weeks
erythema nodosum: causes
- Infections – Streptococcus, Upper respiratory tract
- Inflammatory bowel disease
- Sarcoidosis
- Drugs – OCP, Sulphonamides, Penicillin
- Mycobacterial Infections
- Idiopathic
dermatitis herpetiformis
- Rare but persistent immunobullous disease that has been linked to coeliac disease
- Itchy blisters can appear in clusters
- Often symmetry
- Scalp, shoulders, buttocks, elbows and knees
- Detailed history
- Coeliac screening
- Skin biopsy
- Emollients, gluten free diet, topical steroids, dapsone
urticaria
- Wheals/hives
- Associated angioedema (10%)
- Areas of rash can last from few minutes up to 24 hours
- Acute <6 wks.
- Chronic >6 wks.
urticaria: causes
o Viral infection o Bacterial infection o Food or drug allergy o NSAIDS, OPIATES, o Vaccinations o Chronic urticaria – idiopathic often no cause found. Likely autoimmune cause.
urticaria: treatment
o Consider possible triggers including medication and withdraw o Antihistamines § Newer generation e.g. desloratadine § 3 x daily (off licence doses) § Ranitidine § Montelukast § Omalizumab § Ciclosporin
