Dermatology Flashcards
What is the most common type of exzema?
Atopic excema
What is atopy?
overactive immune response to environmental stimuli
What is the atopic march?
tendency to 3 commonly linked conditions:
ECZEMA, ASTHMA and HAYFEVER
Atopic exzema is caused by an abnormality in the expression of which protein?
Abnormality in filaggrin expression.
Distribution of atopic exzema
- Infancy
- Typically starts on the face/neck (cheeks common), can spread more generally
- Older children
- Flexural pattern predominates (antecubital fossae, popliteal fossae, wrists, hands, ankles)
Childhood exzema flares can be associated with:
- Infections/viral illness
- Environment: central heating, cold air
- Pets: if sensitised/allergic
- Teething
- Stress
What type of exzema is this?
Which parts of the body does it affect?
What age group does it affect?
Treatment
- Seborrheoic dermatitis
- Mainly scalp and face
- Often babies under 3 months, usually resolves by 12 months
- Emollients, antifungal creams, antifungal shampoos, mild topical steroids
What type of exzema is this?
- Discoid exzema
- Scattered annular/circular patches of itchy eczema
- Can occur in this pattern as part of atopic eczema or in isolation
What type of exzema is this?
Which body part is it found on?
Characteristics
- Pomphylx eczema
- Hand and foot exzema
- Characterised by vesicles; can be intensly itchy
What are the two types of exogenous exzema?
- Allergic eczema
- sensitised to allergen
- Type IV hypersensitivity - patch testing helpful
- Irritant eczema
- repeated contact; water and soaps, touching irritant foods; citrus, tomatoes, chemical irritants
Symptoms of immediate reactions from food allergy
- lip swelling
- facial redness/itching
- anaphylactoid symptoms
(Type 1 reaction)
Symptoms of late reactions to food allergy
- 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
(Type 4 hypersensitivity)
Tests for immediate reaction food allergies
- Blood test for specific IgE antibodies (RAST)
- Skin prick testing
What are some of the causes of immediate reaction allergies
- Commonest: milk, soy, peanuts, eggs
- Airborne allergens - house dust mite, pet dander, pollens
How would you confrim the allergy for late reaction food allergies?
- Dietary restrictions/eliminations 6-8 weeks
- Eliminate one food at a time
Exzema treatment
- Emollients
- Topical steroids
- Calcineurin inhibitors (e.g protopic – steroid sparing topical agents)
- UVB light therapy
- Immunosuppressive medication
Side effects of prolonged use of topical steroids
Skin thinning
How are creams measured?
Finger tip unit
What type of skin infection is this?
How does transmission take place?
Describe the lesions
How long does it take to clear?
Management
- Molluscum contagiosum
- Transmission to close direct contacts
- Pearly papules, umbilicated centre
- Can take up to 24 months to clear
- Reassurance + 5% Potassium Hydroxide
What is this skin infection?
Which bacteria is this superficial skin infection caused by?
Describe the skin
Treatment
- Impetigo
- Staph aureus
- Pustules and honey-coloured crusted erosions
- Topical antibacterial (fucidin); Oral antibiotic (flucloxacillin)
What is this skin condition?
What is it caused by?
How is it transmitted?
Treatment
- Viral warts
- Human papiloma virus
- Transmitted by direct skin contact
- Topical treatments such as salicylic acid and paring; Cryotherapy
What does this picture show?
What is the most common cause for this in children?
Chicken pox
What are the symptoms of varicella zoster?
- Red papules (small bumps) progressing to vesicles (blisters) often start on the trunk
- Itchy
- Associated with viral symptoms
When is varicella zoster contageous?
Contagious 1-2 days before rash appears and until lesions have crusted.
What is this picture showing?
Describe the lesions
What areas does this occur?
How long does it take to resolve?
- Erythema Nodosum
- Painful, erythematous subcutaneous nodules
- Over Shins; sometimes other sites
- Slow resolution - like bruise, 6-8 weeks
Causes of erythema nodosum
- Infections - Streptococcus, Upper respiratory tract
- Inflammatory bowel disease
- Sarcoidosis
- Drugs - OCP, Sulphonamides, Penicillin
- Mycobacterial infections
- Idiopathic
What does this picture show?
What can cause this?
Treatment
- Wheals / hives
- Viral infection; bacterial infection; food or drug allergy; NSAIDS, opiates; vaccinations
- Antihistamines 3x daily
