Dermatology Flashcards
What is Purpura?
Bleeding of superficial vessels
What does purpura look like?
Red/purple non-blanching petechiae
What causes purpura?
Infection: MENINGITIS, Hib, Chicken Pox, Sepsis, Enterovirus
Other: Clotting disorders (dec platelets, HUS, DIC), thrombocytopenia, vasculitis, trauma, drug reactions, vasomotor straining
How is purpura investigated?
Bloods: FBC, CRP, LFT, Clotting (platelets), INR, autoantibody screen
Blood Film & cultures
Urinalysis
How is purpura managed?
Treat cause
Platelets: Transfusion
What factors exacerbate eczema?
Infection Allergen/Irritant Heat & humidity Medical changes Physiological stress
How does eczema present?
Early: Erythema, scaling, itching/excoriation, vesicles, weeping, sleep disturbance
Late: Lichenification
At what age is each body part affected with eczema?
Infancy: Face, trunk, extensors
Child: Antecubital fossa, knee flexures, neck
Adolescent: Hands, feet, limb flexures
How is mild eczema managed?
Emollients TDS
Mild topical steroid: Hydrocortisone BD 3-5days
How is moderate eczema managed?
Emollients TDS
Moderate topical steroid: Eumovate 7-14days
Topical calcineurin inhibitor: Tacrolimus/Pimecrolimus
Bandages & dressings
How is severe eczema managed?
Emollients TDS
Potent topical steroid: Betnovate/Dermovate 7-14days
Topical calcineurin inhibitor: Tacrolimus/Pimecrolimus
Bandages & dressings
Oral antihistamine: Cetirizine
Phototherapy
How is a diagnosis of atopic eczema made?
Itchy skin PLUS 3 of: Visible flexural dermatitis Hx of flexural dermatitis Hx/FHx of atopy Hx of dry skin in past 12m
What are the different types of birthmarks? Describe them
Salmon patches: Most common, eyelids, forehead, neck, fade after a few months, more noticeable when crying
Haemangioma: Strawberry marks, eyelids, forehead, neck, raised anywhere on body, grow until 6m, gone by 7y, Tx Propanolol (beta blockers)
Capillary Malformations (Port wine): Flat, red/purple, unilateral, rare, face/neck/back, defect in nerve supplying capillaries, hormone sensitive, Tx laser
Cafe au lait: 1-2, >6 see GP, sign of neurofibromatosis
Mongolian blue spot: Gone by 4y, lower back/buttocks
Congenital melanocytic naevi: Moles, overgrowth of pigment cells, most shrink, growth= Ca risk
What are the causes of impetigo?
Staph Aureus
Strep Pyogenes
What are the signs & symptoms of impetigo?
Highly contagious
Erythematous macules become vesicular/bullous on face/neck/hands
Linked to pre-existing skin lesion e.g eczema
Infective until dry
How is impetigo treated?
Topical Fusidic acid: 3-4/day
Oral Fusidic acid: 250mg
12/hrs 5-10days
Avoid School
What is Stevens-Johnson Syndrome?
Aka Toxic epidermal necrolysis
Immune mediated hypersensitivity disorder
What are the signs & symptoms of Stevens-Johnson Syndrome?
Widespread blisters/bullae
On top of erythematous, purple macular or haemorrhage skin
Mucus membranes affected (including mouth)
Nikolsky sign: Rubbing skin causes separation at dermoepidermal junction
Fever
Arthralgia
Myalgia
Prostration
How is Stevens-Johnson Syndrome treated?
Supportive: Hydration (Crystalloid), airway protection, maintain temp Emollients Dressings Antiseptics: Chlorhexidine Specialist eye care Systemic corticosteroids
How is Stevens-Johnson Syndrome investigated?
Skin biopsy
Bloods: FBC, LFTs, U&E, Glucose, Bicarb, Mg, Phosphate
Serology
Mycoplasma
What are the components of the SCORTEN score?
Predict mortality in SJS/TEN Age >40 Malignancy HR >120 Epidermal detachment >10% Serum bicarb <20 Serum urea >10 Serum glucose >14
What are the causes of SJS/TEN?
Drugs: Allopurinol, Anticonvulsants, sulfonamides, NSAIDs, salicylates, antivirals
Vaccinations
Infection: HSV, EBV, HIV, influenza, hep, enterovirus
What are the complications of SJS?
Acute dehydration ARDS Infection GI ulceration, perforation Shock Multiorgan failure DIC
What is the management of nappy rash?
Frequent nappy changes Use nappies w/greatest absorbency Barrier: Zinc Cream Expose to air Severe: 1% Hydrocortisone Candida: Topical Nystatin 6hrly Infection: PO Flucloxacillin 7days
What is the pathophysiology of nappy rash?
Bacterial breakdown of urine
Produces ammonia
Causes contact dermatitis
What skin lesions can be seen in TB infection?
Erythema Nodosum: Painful, inflamed rash on the lower limbs
Lupus Vulgaris: Nodular, painful, disfiguring lesions predominantly on the face.
