Dermatology Flashcards
What is eczema?
Itchy, dry inflammatory skin condition
What are the different types of eczema?
Atopic Seborrhoeic Varicose Pomphylx Discoid Allergic contact dermatitis Irritant contact dermatitis Photosensitive eczema
What is the most common type of eczema?
Atopic
What is a typical presentation of atopic eczema?
Dry, itchy skin on cheeks of infant, flexural surfaces of children
Skin barrier dysfunction –> loss of water, penetration of irritants/allergens
What causes atopic eczema?
Overactive immune response to environmental stimuli –> immune mediated defect in skin barrier function
Abnormality in filaggrin protein which binds keratin together
What are common flares for eczema?
Infection, central heating, cold air, pets, teething, stress
How can you treat eczema?
Emollients (creams, lotions, ointments) Topical steroids (for 1-2weeks BD + wkend dose) Calcineurin inhibitors UVB Immunosuppression
What are the steroids we can use on the skin in order of strength?
Mild - hydrocortisone
Moderate - eumovate (25x)
Potent - betnovate (100x)
Dermovate - 600x
Don’t use above eumovate on face
What is a typical presentation of seborrheic eczema?
Face and scalp
<3m old
clears up by 12m
Gets infected by Malasseizia yeast –> cradle cap
How do you treat seborrheic eczema?
Antifungal cream/shampoo
Emollients
Steroids
How does discoid eczema present?
Annular itchy patches
How does pomphylx eczema present?
Vesicles on palms/soles
How does varicose eczema present?
Oedema/venous insufficiency/varicose veins –> irritation of skin
usually legs which are dry and inflamed/ulcerated
How do you treat varicose eczema?
Emollients, topical steroids, compression stockings
What is allergic contact dermatitis due to?
Sensitisation of an allergy (commonly diary, soy, wheat, dander, pollen etc.)
How might you investigate an allergic contact dermatitis?
Blood test for IgE
Prick testing
What features might be suggestive of a food allergy?
Anaphylaxis, GI probs, late reactions, failure to thrive, severe eczema unresponsive to Rx
What is treatment for allergic contact dermatitis?
Dietary restrictions >8wks
Eliminate 1 food at a time
Dietician input
Reintroduce to see if allergic
What causes irritant contact dermatitis?
Repeated contact with water, citrus, soaps, friction
How can you identify photosensitive eczema?
T-shirt lines
Places not struck by sun unaffected
What is impetigo? What does it present like?
Superficial bacterial infection
Pustules and honey-crusted erosions
What causes impetigo?
Staph aureus
How do you treat impetigo?
Fudicin/flucoxacillin
What does molluscum contagiosum present like?
Pearly, papules, umbilicated centres
Takes 24m to heal
benign
What causes molluscum contagiosum?
Molluscipox virus via direct contact
How do you treat molluscum contagiosum?
Molutrex
What do viral warts appear like?
Skin coloured, non cancerous growths
Known as veruccas on the foot
What causes viral warts?
HPV transmitted by direct contact
How do you treat viral warts?
Stimulate immune system against them using cryotherapy or topical paints (like salicyclic acid)
What is the presentation of a viral exanthems like?
Viral illness assoc (headache, fever, malaise)
Maculopapular rash
What are viral exanthems due to?
Reaction to toxin produced by organism/damage to skin by organism/immune response
What diseases can cause viral exanthems?
Chickenpox, parovirus B12 (slapped cheek), measles, rubella, roseola (herpes virus 6)
What does chickenpox present like?
Red papules progressing to vesicles starting on trunk
Intensely itchy
viral symptoms
What causes chickenpox?
VZV - which is v contagious from 1-2d before symptoms till lesions crusted over
What is rarely associated with chickenpox?
Pneumonia, encephalitis
What does slapped cheek present like?
Erythematous rash over cheeks –> lace like network on trunk/limbs
takes 6 weeks to fade
What cell does parovirus target?
RCs in bone marrow
What can parovirus lead to in vulnerable groups?
Aplastic crisis in those with haemolytic anaemia
Hydrops fetalis/IUD in pregnant woman
What does hand foot and mouth present like?
Blisters on hands, feet, mouth
Viral symptoms
Epidemic in late summer/autum
What usually causes hand foot and mouth?
Enterovirus - usually coxsackie A16
What is orofacial granulomatosis?
Lip swelling/fissuring
May get cobble stone appearance
What causes orofacial granulomatosis?
Crohns
What is erythema nodosum/
Painful, erythematous nodules over shins
Slow resolution
What can cause erythema nodosum?
Infections - strep throat, URTI Sarcoidosis IBD Drugs - OCP, sulphonamide, penicillin Mycobacterial infection Idiopathic
What investigations might you want to do in erythema nodosum?
Serum ACE/check hx of lung probs for sarcoidosis
ASO titre for strep
How do you treat erythema nodosum?
Steroids
What is dermatitis herpetiformis?
Itchy blisters in clusters on scalp, shoulders, buttocks
Usually symmetrical
What is dermatitis herpetiformis linked to?
Coeliac disease
What investigations should you do in dermatitis herpetiformis?
Hx
Coeliac screening
Skin biopsy
How do you treat dermatitis herpetiformis?
Emollients
Gluten free diet
Topical steroids
Dapsone
What is urticaria?
Wheals/hives
Assoc. angioedema
LASTS <24H
What is chronic vs acute urticaria?
Chronic >6wks, acute <6wks
What can cause urticaria?
Viral/bacterial infection, food/drug allergy, NSAIDs/opiates, vaccinations, idiopathic
How do you treat urticaria?
Remove triggers
Antihistamines (desloratadine)
Ranitidine, Montelukast
Omalizumab, cyclosporin
