Derm! Flashcards
What type of surfaces does eczema affect?
Flexor surfaces e.g. inside of elbows and knees
What is the pathophysiology of eczema?
Eczema is caused by defects in the skin barrier. Tiny gaps in the skin barrier provide an entrance for irritants, microbes and allergens that create an immune response, resulting in inflammation and the associated symptoms.
Management of eczema
-Create an artificial barrier over the skin to compensate for the defective skin barrier using emollients that are as thick and greasy as tolerated.
-Emollients used as often as possible, after washing and before bed.
-Soap substitutes
Name some thin creams and thick, greasy emollients
Thin creams:
E45
Diprobase cream
Oilatum cream
Aveeno cream
Cetraben cream
Epaderm cream
Thick, greasy emollients:
50:50 ointment (50% liquid paraffin)
Hydromol ointment
Diprobase ointment
Cetraben ointment
Epaderm ointment
Management of eczema flares
-thicker emollients, topical steroids, wet wraps and treating any complications such as bacterial or viral infections
-zinc impregnated bandages, topical tacrolimus, phototherapy and systematic immunosuppressants, such as oral corticosteroids, methotrexate and azathioprine
What do topical steroids do?
-settle down immune activity
-reduce inflammation
What is telangiectasia?
Enlarged blood vessels under the surface of the skin.
Topical steroid side effects
-thinning the skin, which can make the skin more prone to flares, bruising, tearing, stretch marks and enlarged blood vessels under the surface of the skin called telangiectasia.
-depending on the location and strength of the steroid there may be some systemic absorption of the steroid.
What is the steroid ladder?
Mild: Hydrocortisone 0.5%, 1% and 2.5%
Moderate: Eumovate (clobetasone butyrate 0.05%)
Potent: Betnovate (betamethasone 0.1%)
Very potent: Dermovate (clobetasol propionate 0.05%)
What is the most common bacterial organism in eczema? And what is the treatment?
-Staphylococcus aureus
-Oral Flucloxacillin
What is eczema herpeticum?
A viral skin infection in patients with eczema caused by the herpes simplex virus (HSV) or varicella zoster virus (VZV)
What is psoriasis?
Psoriasis is a chronic autoimmune condition that causes recurrent symptoms of psoriatic skin lesions.
Describe psoriatic skin lesions
Patches of psoriasis are dry, flaky, scaly, faintly erythematous skin lesions that appear in raised and rough plaques, commonly over the extensor surfaces of the elbows and knees and on the scalp. These skin changes are caused by the rapid generation of new skin cells, resulting in an abnormal build-up and thickening of the skin in those areas.
What is the most common type of psoriasis in adults?
Plaque psoriasis
Guttate psoriasis is often triggered by a …
streptococcal throat infection- more common in children
Name a few specific signs suggestive of psoriasis
-Auspitz sign= small points of bleeding when plaques are scraped off
-Koebner phenomenon= the development of psoriatic lesions to areas of skin affected by trauma
-Residual pigmentation of the skin after the lesions resolves
Management of psoriasis
-topical steroids
-topical vitamin D analogues (calcipotriol)
-topical dithranol
-topical calcineurin inhibitors (tacrolimus)- usually only in adults
-phototherapy with narrow band ultraviolet B light is particularly useful in extensive guttate psoriasis
-Dovobet and Enstilar contain both a potent steroid and vitamin D analogue.
-Where topical treatment fails, children may be started on unlicensed systemic treatment e.g., methotrexate, cyclosporine, retinoids or biologic medications
What is Guttate psoriasis?
Guttate psoriasis is the second most common form of psoriasis and commonly occurs in children. It presents with many small raised papules across the trunk and limbs. The papules are mildly erythematous and can be slightly scaly. Over time the papules in guttate psoriasis can turn into plaques. Guttate psoriasis is often triggered by a streptococcal throat infection, stress or medication. It often resolves spontaneously within 3-4 months.
Name some associations of psoriasis
-Nail psoriasis- nail pitting, thickening, discolouration, ridging and onycholysis (separation of the nail from the nail bed).
-Psoriatic arthritis- occurs in 10-20% of patients with psoriasis
-Psychological implications of having chronic skin lesions
Other co-morbidities that increase the risk of cardiovascular disease are associated with psoriasis, particularly obesity, hyperlipidaemia, hypertension and type 2 diabetes.
What is impetigo?
Impetigo is a superficial bacterial skin infection, usually caused by the staphylococcus aureus bacteria.
Impetigo is contagious.
Impetigo occurs when bacteria enter via a break in the skin.
Impetigo can be classified as non-bullous or bullous.
What is a golden crust a characteristic of?
Staphylococcus skin infection
Causes of impetigo
-staphylococcus aureus
-streptococcus pyogenes
What are the complications of impetigo?
-cellulitis
-sepsis
-scarring
-post streptococcal glomerulonephritis
-staphylococcus scalded skin syndrome
-Scarlet fever
Describe non-bollous impetigo
-typically around the nose or mouth
-the exudate from the lesions dries to form a golden crust
-topical fusidic acid - antibiotic
-antiseptic cream (hydrogen peroxide 1% cream)
-oral flucloxacillin (widespread or severe)
Describe bullous impetigo
-always caused by staphylococcus aureus bacteria- these bacteria can produce epidermolytic (detachment or loosening of the epidermis) toxins that can break down keratin- this causes 1-2 cm fluid filled vesicles to form, which eventually burst and heal without scarring- lesions are painful and itchy
-more common in neonates
-systemic symptoms- fever, malaise
-in severe infections when the lesions are widespread, it is called staphylococcus scalded skin syndrome
-swabs confirm diagnosis
-flucloxacillin to treat
What is urticaria?
Urticaria are also known as hives. They are small itchy lumps that appear on the skin. They may be associated with a patchy erythematous rash. This can be localised to a specific area or widespread. They may be associated with angioedema and flushing of the skin. Urticaria can be classified as acute urticaria or chronic urticaria.
Pathophysiology of urticaria
Urticaria are caused by the release of histamine and other pro-inflammatory chemicals by mast cells in the skin. This may be part of an allergic reaction in acute urticaria or an autoimmune reaction in chronic idiopathic urticaria
What are the causes of acute urticaria?
Acute urticaria is typically triggered by something that stimulates the mast cells to release histamine. This may be:
-allergies to food, medications or animals
-contact with chemicals, latex or stinging nettles
-medications
-viral infections
-insect bites
-dermatographism (rubbing of the skin)
What are the triggers of chronic inducible urticaria?
-sunlight
-temperature
-exercise
-strong emotions
-hot or cold weather
-pressure (dermatographism)
What is autoimmune urticaria?
Autoimmune urticaria describes chronic urticaria associated with an underlying autoimmune condition, such as systemic lupus erythematosus.
What is chronic idiopathic urticaria?
Recurrent episodes of chronic urticaria without a clear underlying cause or trigger
What is chronic urticaria?
Chronic urticaria is an autoimmune condition, where autoantibodies target mast cells and trigger them to release histamines and other chemicals. It can be sub-classified depending on the cause:
-chronic idiopathic urticaria
-chronic inducible urticaria
-autoimmune urticaria
What is acute urticaria?
Acute urticaria is typically triggered by something that stimulates the mast cells to release histamine.
What is ringworm?
Ringworm is a fungal infection of the skin.
AKA tinea and dermatophytosis.
What is the most common type of fungus that causes ringworm?
Trichophyton
-spread through contact with infected individuals, animals or soil
What is tinea capitis?
ringworm affecting the scalp
What is tinea pedis
Ringworm affecting the feet aka athletes foot
What is tinea cruris?
ringworm of the groin
what is tinea corporis?
ringworm on the body
What is onychomycosis?
fungal nail infection
Presentation of ringworm?
-an itchy rash that is erythematous, scaly and well demarcated
-rings or circular
-the edge is more prominent and red and the area in the centre is more faint in colour
how does tinea capitis present?
-well demarcated hair loss
-itching, dryness and erythema of the scalp
-more common in children
how does tinea pedis present?
-white or red, flaky, cracked, itchy patches between the toes
-the skin may split or bleed
how does onychomycosis present?
thickened, discoloured and deformed nails
What is the management of ringworm?
Anti-fungal medications:
-creams e.g. clotrimazole and miconazole
-shampoo e.g. ketoconazole
-oral e.g. fluconazole, griseofulvin and itraconazole
Management of fungal nail infections
-amorolfine nail lacquer for 6-12 months
-resistant cases may need oral terbinafine
-a mild topical steroid to settle the inflammation and itching- e.g. miconazole 2% and hydrocortisone 1% cream (Daktacort)
What is tinea incognito?
-a more extensive and less well recognised fungal skin infection that results from the use of steroids to treat an initial fungal infection
-this often occurs when the initial presentation of ringworm was misdiagnosed as dermatitis and a topical steroid was prescribed- fungal growth is accelerated by dampening the immune response in the local area
What is actinic keratoses?
-dysplastic epidermal lesions
-considered precursors to SCC
-arise due to chronic UV radiation exposure
-characterised by rough, scaly patches or papules on sun-exposed skin
-predominantly in fair-skinned, elderly individuals
Clinical features of actinic keratoses
-small, crusty or scaly lesions
-may be pink, red, brown or the same colour as the skin
-typically on sun-exposed areas e.g. temples of head
-multiple lesions may be present
Management of actinic keratoses
-prevention of further risk- sun cream
-fluorouracil cream- anti-metabolites - side effect= red and inflamed skin
-topical diclofenac- NSAID
-topical imiquimod- immune response modifiers
-cryotherapy
-curettage and cautery