Week 2 Flashcards
What are the two main types of topical therapy
Topical steroids
emollients
What is the main purpose of emollient use?
They enhance epidermis rehydration in dry/scaly skin conditions.
What form of therapy is used to treat severe eczema in young children?
Wet wrap therapy
Identify four possible side effects of topical steroids
Rosacea stretch marks purpura skin thinning perioral dermatitis telangectasia
What are the three modes of action of topical corticosteroids?
vasoconstrictive
anti-inflammatory
immunosuppressant
Modrasone, Clobetasone, Butyrate, Mometasone, Betamethasone, Valerate are all examples of what type of drug?
Topical corticosteroids
Povidone iodine , Chlorhexidine , Triclosan , Hydrogen peroxide are all examples of what type of drug? Give three uses for such drugs
Antiseptics
recurrent skin infections, skin cleansing, wound irrigation
Give three skin conditions which may be treated with antibiotics
rosacea impetigo acne cellulitis folliculitis carbuncles Staphloccocal scalded skin syndrome erysipelas necrotising fasciitis gas gangrene (clostridium)
Identify three skin infections that are treated with antiviral agents
herpes zoster (shingles)
herpes simplex
eczema herpeticum
Identify three skin conditions which require anti-fungal treatment
candida (thrush)
dermatophytes (ringworm)
pityriasis versicular
What is the purpose of keratolytic drugs?
They soften keratin e.g. viral warts, hyperkeratotic eczema and psoriasis, corns, calluses
Identify 6 possible topical treatments of psoriasis
emollients keratolytics Vit D analogues coal tar topical steroid dithranol
What is hyperkeratosis?
Increased thickness of the keratin layer.
What is parakeratosis?
Persistence of nuclei in the keratin layer
What is acanthosis?
Increased thickness of epithelium
What is papillomatosis
Irregular epithelial thickening
What is spongiosis?
Oedema between the squamous cells
What are the four main reaction patterns of inflammatory skin conditions?
psoriasiform- elonagtion of rete pegs
spongiotic- intraepidermal oedema
lichenoid- basal layer damage
vesiculobullous- blistering
What is lichen planus? What are its main characteristics? How is it usually treated?
Idiopathic chronic inflammatory skin disease.
Characterised by intensely pruritic, purple papules effecting flexural aspect of wrists, forearms and lower legs. Also effects oral mucosa
responds well to corticosteroids
What is pemphigus? what is the most common form of pemphigus?
A rare autoimmune bullous disease where there is loss in keratinocyte adhesion
Pemphigus vulgaris
What process is common to all forms of pemphigus?
acantholysis- lysis of intercellular cell adhesion sites
What auto-antibodies are evident in pemphigus vulgaris?
IgG auto-antibodies against desmoglein 3 (a desmosomal protein) leading to loss of keratinocyte adhesion
Dermatitis herpetiformis is the cutaneous manifestation of what disease?
Coeliac disease
Identify 4 possible symptoms of an allergic reaction
urticaria
angioedema
wheezing
anaphylactic shock
What are the two main allergy investigations?
Skin prick testing
challenge testing
How do you treat anaphylactic shock?
adrenaline autoinjector
What is the name of allergens that effect the skin? Give some examples
Haptens
tattoo ink, fragrances, latex, plants
Identify 4 antibiotics which could be used to treat MRSA
doxycycline
clindamycin
vancomycin
co-trimoxazole
What are excoriations?
scratch marks
What is the alternative name for dermatitis?
exzema
What is pruritis?
The medical term for itch
Where is pruritis processed?
Forebrain and hypothalamus
Which nerves transmit itch?
Unmyelinated C fibres
Itch is associated with mediators released from ______ _____ ___________.
Mast cell degranulation
Identify four causes of itch
Pruritoceptive- inflammation/dryness triggers
Neuropathic- due to damage to central or peripheral nerves
Neurogenic- no damage but caused by e.g. opiate effects on CNS
Psychogenic- psychological e.g. delusion of infestation
Identify some risk factors for drug eruptions
age
female>males
genetics
concomitant diseases
Exanthematous drug reactions appear as a widespread ____________ rash. They are _____ mediated drug reactions (type ____ hypersensitivity) and are related to ___________ use.
maculopapular
T-cell
IV
Antibiotic
What is the difference between macules and papules?
Macules are flat non-palpable lesions whereas
Papules are small <0.5cm palpable lesions
Uriticarial drug reactions either are a matter of ______ mediated hypersensitivity and erupt upon ________ exposure or are caused by direct release of _______ ________ from mast cells upon _________ exposure.
IgE secondary inflammatory mediators mast cells first
Identify four types of drug which could cause fixed drug eruptions
Tetracyclines, doxycycline
NSAIDS
Carbamazepine (anti-convulsant)
Paracetamol
Identify four severe cutaneous drug eruptions
Toxic Epidermal Necrolysis
Stevens-Johnson syndrome
Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)
Acute Generalised Exanthematous Pustulosis
Identify four drugs which commonly cause phototoxicity
Amiodarone Doxycycline Quinine Chlorpromazine Thiazide NSAIDs PPIs
Which two hormones are raised in obesity and have skin manifestations?
Androgens
Insulin
Why is there increased androgen production in obesity?
Increased peripheral fat where androgen production can occur
Identify 2 skin manifestations of hyperinsulinaemia
Acanthosis Nigricans
Skin tags- Acrochordons
Identify 4 skin manifestations of hyperandrogenaemia
Hirsutism- male pattern hair growth
Androgenetic Alopecia- male pattern hair loss
Acne- increased sebaceous gland activity
Hidradenitis suppurativa
How come obesity causes lymphoedema? How come Lymphoedema can lead to cellulitis?
Increased subcutaneous fat mass leads to reduced lymphatic drainage leading to swelling. Persistent oedema leads to chronic inflammation and fibrosis. Reduced oxygen supply allows bacterial overgrowth leading to cellulitis
What vascular pathology may be exacerbated by abdominal obesity?
Chronic venous insufficiency because abdominal obesity inhibits venous return
Identify 5 skin diseases that are exacerbated by obesity
Chronic venous insufficiency lymphoedema psoriasis skin infections Intertigo- macerated skin plaques that occur in skin folds
What disease can result form Vitamin B3 deficiency (Niacin)?
Pellagra (Dermatitis, delirium, diarrhoea, death)
What are the characteristic clinical features of Psoriasis? Name some of the other presentations of psoriasis
Well-demarcated, red plaques with thick scale.
appear on elbows, knees, scalp and elsewhere.
Guttate, erythrodermic, pustular, psoriatic arthritis, enthesis, nail changes
What type of psoriasis is prevalent in heavy smokers?
Erythrodermic and pustular psoriasis
Give two examples of Vitamin D analogues
Calcitriol, tacalcitrol, calcipotriol
What are the characteristic features of Lichen planus
Characterised by intensely pruritic pink-purple polygonal plaques effecting flexural aspect of wrists, forearms, lower legs.
How is Lichen planus treated?
Potent corticosteroids
How does Pemphigus vulgaris present? How is it treated?
Presents as blisters which rupture leaving behind shallow erosions.
Systemic corticosteroids
Describe the pathophysiology of Bullous pemphigoid
Autoantibodies against hemidesmosomes cause basement membrane split at the dermo-epidermal junction. Appears as large haemorrhagic/serous blisters.
What are comodones?
Swollen and inflamed pilosebaceous units
Describe the presentation of acne
Comodones, blackheads, macules and papules of the skin distributed on the face, neck, upper back, anterior chest.
Describe some of the treatments of acne vulgaris
Topical retinoids topical benzoyl peroxide oral lymecycline tetracyclines oral contraceptive pill Isotretinoin (in severe acne)
What is telangiectasia?
Dilated venules at skin surface which appear as red meshworks
Demodex mites are associated with what skin condition?
Rosacea
How is rosacea treated
Topical metronidazole
azelaic acid/invermectin
tetracyclines/doxycyclines
Describe a typical presentation of eczema
Usually in infancy
dry, red, pruritic skin with excoriations and lichenification
Flexures of elbows, knees, ankles, wrists
Experience period where controlled and also flares
Describe the pathophysiology of atopic eczema
Patient has Genetic filaggrin deficiency and so the keratinocyte barrier is impaired and antigenic material can penetrate the skin easier. These antigens and microbes activate CD4 T cells resulting in raised interluikins. Mast cells degranulate releasing IgE antibodes.
What protein deficiency is shown in atopic eczema?
Filaggrin deficiency
Describe the management of eczema during 1. maintenance and 2. flares
- Regular use of emollients, avoid environmental triggers
- Emollients and topical steroids, treat complications with antibiotics
possible zinc wet wraps, phototherapy, immunosuppressants such as methotrexate and azathioprine, topical tacrolimus
Name some possible environmental triggers of atopic eczema
change in temperature plants washing agents dietary products emotional stress
Identify the cardinal features of eczema (dermatitis)
pruritis
erythema
excoriations
lichenification
What is lichenification?
Prominent lines from repeated scratching
Give three histological features of eczema
spongiosis, hyperkeratosis, acanthosis
What is the difference between allergic dermatitis and irritant contact dermatitis?
Allergic dermatitis shows type 4 hypersensitivity and is a reaction to allergens whereas irritant contact dermatitis is due to frequent contact with an irritant.
What is tuberous sclerosis? What characterises this condition?
It is a genetic condition that is characterised by hamartomas in various organs. Hamartomas are benign neoplastic lesions of the tissue from which they originate
What gene mutations are found in tuberous sclerosis?
Mutations of TSC1 (tuberin) and TSC2 (Hamartin). Hamartin and tuberin interact with one another to control the growth and size of cells
What are the main skin manifestations of tuberous sclerosis?
Cafe-au-lait spots poliosis ash leaf hyperpigmentation subungal fibroma angiofibroma Shagreen patches
Define neurofibromatosis type 1
A condition characterised by nerve tumours in the nervous system and caused by mutation of the NF1 gene on chromosome 17 which codes for neurofibromin which is a tumour suppressor gene
Name the 7 possible diagnostic criteria for NF1 which is shortened by the pneumonic CRABBING
Cafe-au-lait spots Relative with NF1 Axillary or inguinal freckles Bony dysplasia such as Bowing of a long bone or sphenoid wing dysplasia Iris Hamartomas (Lisch nodules) Neurofibromas Glioma of optic nerve
What are erysipelas?
Localised skin infection caused by Strep pyrogenes
What is the treatment of choice for scabies?
Permethrin cream
