Paed Dermatology Flashcards
What is eczema?
Itchy, dry inflammatory skin disease
Types of eczema
Endogenous (internal cause)
- Atopic
- Seborrhoeic - face / scalp - scale associated
- Discoid - annular/circular patches
- Pomphylx - vesicles affecting palms/soles
- Varicose - oedema/venous insufficiency
Exogenous (external cause)
- allergic contact dermatitis (sensitised to allergen)
- irritant contact dermatitis (friction, cold, chemicals e.g. acids, alkalis, detergents, solvents)
Photosensitive/photaggravated eczema
Flares of childhood eczema can be associated with…..
Infections/viral illness environment - central heating - cold air Pets if sensitised/allergic Teething Stress Sometimes no cause for flare
What is the most common type of eczema, especially in children?
Atopic eczema
What is atopy?
Overactive immune response to environmental stimuli
Pathology of atopic eczema
Immune mediated defects in the skin barrier function - dry inflamed skin
The “skin barrier defect”
Associations of atopic eczema
Usually 1 or more family members affected
3 conditions that atopy is often linked to
Asthma
Eczema
Hayfever
Where is atopic eczema seen in infancy?
Typically starts on face/neck (cheeks common)
Can spread more generally
Where is atopic eczema seen in older children?
Flexural pattern predominates (antecubital fossae, popliteal fossae, wrists, hands, ankles)
Facial eczema also possible / can recur
What is there an abnormality in in atopic eczema?
Filaggrin expression
What is the roles of filaggrin?
Bind the keratin filaments together
Play a role in producing natural moisturing factor
What is the features of the loss of skin barrier function of atopic eczema?
Loss of water
Irritants may penetrate (soap, detergents, solvents, dirt)
Allergens may penetrate (pollens, dust mite antigens, microbes)
Who and where is seborrheoic dermatitis mainly seen?
Babies under 3 months
Mainly scalp and face
When does seborrheic dermatitis usually resolve by?
12 months
Associations of seborrheoic dermatitis
proliferation of various species of the skin commensal malassezia in its yeast form
Cradle cap in infants
Treatment of seborrheic dermatitis
emollients
antifungal creams
antifungal shampoos
mild topical steriods
What is discoid eczema?
Scattered annular/circular patches itchy eczema
What can discoid eczema also occur as a part of?
Atopic eczema
Presentation of pomphylx eczema
hand and foot eczema
Characterised by vesicles
Can be intensely itchy
What does varicose eczema affect?
Legs in association with venous insufficienct
Associations of varicose eczema
Oedema
varicose veins
chronic leg swelling
Presentation of varicose eczema
Skin often dry and inflamed
may ulcerate
Treatment of varicose eczema
emollients
topical steroids
compression stockings
What is helpful in determining allergic eczema?
Allergic eczema
Causes of irritant eczema
Repeated contact water and soaps citrus tomatoes chemical irritants
What does eczema =?
Dermatitis
What % of childhood eczema is mild?
80%
Presentation of food allergy
Lip swelling facial redness / itching anaphylactoid symptoms Late reactions - worsening of eczema 24/48 hours after ingestion GI problems failure to thrive Severe eczema unresponsive to treatment Severe generalised itching - even when the skin appears clear
What can be associated with food allergy?
Atopy
2 ways to test for food allergy
Blood test for specific IgE antibodies to certain foods
Skin prick testing
Commonest food allergies
Milk / dairy Soy Peanuts Eggs Wheat Fish
Airborne allergens
house dust mite
pet dander
pollens
How to find out if you are allergic to a food
dietary restrictions / eliminations > 8 weeks
Eczema treatment
Emollients - lotions - creams / ointments Topical steroids Calcineurin inhibitors (e.g. protopic - steroid sparing topical agents) UVB light therapy Immunosuppressive medication
Features of emollients used for treatment of eczema
Fragrance free
Greasier ointments for effective
S/Es of topical steroids
Skin thinning in prolonged use
Topical steroid phobia
Types of topical steriods
Very potent (dermovate) - 600x
Potent (betnovate) 100x
Moderate (eumovate) 25x
Mild (hydrocortisone)
How much topical steroids should be used?
Finger tip unit
How to use topical steriods
Once daily for 1 - 2 weeks
if improvement then use alternate days for a few more days
Then if stubborn/persistent areas can use twice weekly in these areas
If at any point the eczema starts flaring, go back to daily applications
Treatment of impetigo
Topical antibacterial (Fucidin) Oral antibiotic (flucloxacillin)
What is molluscum contagiosum caused by?
Molluscipox virus
incubation of molluscum contagiosum
2 weeks to 6 months
Transmission of molluscum contagiosum
close direct contacts
Presentation of molluscum contagiosum
Pearly papules
Umbilicated centre
How long can molluscan contagiousum take to clear?
Up to 24 months
Treatment of molluscan contagiousum
5% potassium hydroxide
Presentation of viral warts
Often skin coloured
Sole of the foot - verruca
What are viral warts?
Common non cancerous growths of the skin caused by an infection with HPV
What do viral warts do?
Stimulate own immune system to respond
Treatment of viral warts
cryotherapy Topical paints (salicylic acid)
How much of viral warts resolve in 24 months?
90%
Presentation of viral exanthems
Fever
Malaise
Headache
Pathology of viral exanthems
Either reaction to a toxin produced by the organism, damage to the skin by the organism or an immune response
Associated viral illnesses of viral exanthems
chicken pox measles rubella roseola (herpes virus 6) erythema infectiosum (paravirus B19, slapped cheek)
What happens once have the varicella zoster infection?
Life long immunity
Who is susceptible to chicken pox at all times?
Immunocompromised
Presentation of chicken pox
red papules (small bumps) progressing to vesicles (blisters) often start on trunk itchy associated viral symptoms
Incubation period of chicken pox
10-21 days
When is chicken pox contagious?
1-2 days before rash appears and until lesions have crusted
What is chicken pox rarely associated with?
Pneumonia
Encephalitis
Incubation of parvovirus (slapped cheek)
7 - 10 days
Presentation of parvovirus
Erythematous rash cheeks initially and then also lace like network rash (trunk and limbs)
viral symptoms
mild self limiting illness
How long can parvovirus take to full fade?
6 weeks
What does the virus in parvovirus target?
Red cells in bone marrow
Complications of parvovirus (rare)
Aplastic crisis (if haemolytic disorders) Risks to pregnant women - spontaneous abortion - IU death - hydrops fetalis
What causes hand foot and mouth disease?
Enterovirus
- coxsackie virus A16
- enterovirus 71
Presentation of hand foot and mouth disease
blisters on the hands
Feet and in the mouth
Viral symptoms
When is there epidemics of hand foot and mouth disease?
Late summer
Autumn months
Treatment of hand foot mouth disease
Supportive
Presentation of orofacial granulomatosis
lip swelling and fissuring
oral mucosal lesions
- ulcers and tags
- cobblestone appearance
Common cause of orofacial granulomatosis
Crohn’s disease
Presentation of erythema nodosum
Painful, erythematous subcutaneous nodules
Over shins
Sometimes other sites
Resolution time of erythema nodosum
Slow resolution like a bruise 6 - 8 weeks
Causes of erythema nodosum
infectious - streptococcus - upper resp tract IBD Sarcoidosis Drugs - OCP - Sulphonamides - penicillin Mycobacterial infections Idiopathic
What is dermatitis Herpetiformis?
Rare but persistent immunoglobullous disease that has been linked to coeliac disease
What is dermatitis herpetiformis linked to?
Coeliac disease
Presentation of dermatitis herpetiformis
Itchy blisters that can appear in clusters
often symmetry
scalp, shoulders, buttocks, elbows, knees
Treatment of dermatitis herpetiformis
Emollients
Gluten free diet
Topical steroids
Dapsone
What is urticaria also known as?
Wheals / hives
Associations of urticaria
Angioedema (10%)
How long can urticaria rash last for?
From a few mins up to 24 hours
Types of urticaria
Acute ( < 6 weeks)
Chronic ( > 6 weeks)
Causes of urticaria
Viral infection Bacterial infection Food or drug allergy NSAIDs, Opiates Vaccinations Idiopathic
Treatment of urticaria
Consider possible triggers, including medication and withdraw
Antihistamines
- desloratadine
What is joint pain and a salmon pink rash indicative of?
Systemic onset JIA
