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
What is the most common type of cancer in the Western world?
Basal cell carcinoma
Clinical features of basal cell carcinoma
-most common type is nodular
-sun-exposed sites, especially the head and neck
-initially a pearly, flesh-coloured papule with telangiectasia
-may later ulcerate leaving a central crater
What are the management options for basal cell carcinoma?
-surgical removal
-curettage
-cryotherapy
-topical cream: imiquimod, fluorouracil
-radiotherapy
What are the 2 types of contact dermatitis?
-irritant contact dermatitis- non-allergic reaction due to weak acids or alkalis (e.g. detergents)- often seen on the hands, erythema is typical, crusting and vesicles are rare
-allergic contact dermatitis- type IV hypersensitivity reaction- uncommon, often seen on head following hair dyes- presents with acute weeping eczema which predominately affects the margins of the hairline rather than the hairy scalp itself- topical treatment with a potent steroid is indicated
What is a frequent cause of contact dermatitis?
Cement is a frequent cause of contact dermatitis. The alkaline nature of cement may cause an irritant contact dermatitis whilst the dichromates in cement also can cause an allergic contact dermatitis
What are telangiectasia
Small, widened blood vessels on the skin- spider veins
What is actinic keratoses?
Actinic keratoses are premalignant skin lesions caused by chronic exposure to ultraviolet (UV) radiation, typically seen in fair-skinned individuals and those with a history of outdoor work such as builders. The appearance of these lesions as erythematous, rough patches is consistent with actinic keratoses. In some cases, they can progress to squamous cell carcinoma if left untreated.
Name a non-sedating antihistamine
loratadine or cetirizine
Which drugs exacerbate plaque psoriasis?
Beta blockers
What is cellulitis?
Cellulitis is an infection of the skin and soft tissues underneath.
Cellulitis presentation
-erythema
-warm or hot to touch
-tense
-thickened
-oedematous
-bullae (fluid-filled blisters)
-a golden-yellow crust indicates a Staphylococcus aureus infection
What are the most common causes of cellulitis?
-Staphylococcus aureus
-Group A streptococcus (mainly streptococcus pyogenes)
-Group C streptococcus (mainly streptococcus dysgalactiae)
-MRSA should be considered, particularly in patients with repeated hospital admissions and antibiotics)
What is the Eron classification?
The Eron classification assesses the severity of cellulitis:
Class 1 – no systemic toxicity or comorbidity
Class 2 – systemic toxicity or comorbidity
Class 3 – significant systemic toxicity or significant comorbidity
Class 4 – sepsis or life-threatening infection
Management of cellulitis
-Class 3 and 4 cellulitis requires admission for intravenous antibiotics. Admission is also considered for frail, very young or immunocompromised patients and those with facial, periorbital or orbital cellulitis.
-Flucloxacillin is the usual first-line antibiotic for cellulitis, either oral or IV. It is particularly effective against Staphylococcus aureus and also works well against other gram-positive cocci.
What is folliculitis?
Folliculitis means an inflamed hair follicle due to any cause. The result is a tender red spot, often with a surface pustule.
What causes folliculitis?
-infection, occlusion, irritation and various skin diseases
-bacterial= staph aureus
-Spa pool folliculitis is due to infection with Pseudomonas aeruginosa
-yeast= Pityrosporum ovale (Malassezia), Candida albicans
-Fungi- tinea capitis
-Viral = HSV, herpes zoster, Molluscum contagiosum
-Demodicosis= colonisation by hair follicle mites (demodex)
What are head lice?
-Pediculus humanus captitis parasite
-nits are egg shells that have hatched or contain unviable embryos and not the lice themselves
How are head lice spread?
Transmission is by head to head contact or by sharing equipment like combs or towels
Presentation of head lice
-itchy scalp
-often the nits (eggs) and even lice themselves are visible
Management of head lice
-Dimeticone 4% lotion
-special fine combs- detection combing
-The Bug Buster kit
What are scabies?
-Scabies are tiny mites called Sarcoptes scabiei that burrow under the skin causing infection and intense itching.
-It can take up to 8 weeks for any symptoms or rash to appear after the initial infestation
Presentation of scabies?
-incredibly itchy small red spots, possibly with track marks where the mites have burrowed
-the classic location of the rash is between the finger webs
Management of scabies
-permethrin cream
-oral ivermectin
-crotamiton cream for itching
What is crusted scabies / Norwegian scabies?
-a serious infestation with scabies in patients that are immunocompromised
-patches of red skin that turn into scaly plaques
What is the medical name for acne?
Acne vulgaris
Pathophysiology of acne vulgaris
-Acne is caused by chronic inflammation, with or without localised infection, in pockets within the skin known as pilosebaceous unit.
-The pilosebaceous units are tiny dimples in the skin that contain the hair follicles and sebaceous glands -> produce the natural skin oils and sebum
-Acne results from increased production of sebum, trapping of keratin (dead skin cells) and blockage of the pilosebaceous unit. This leads to swelling and inflammation in the pilosebaceous unit. Androgenic hormones increase the production of sebum, which is why acne is exacerbated by puberty and improves with anti-androgenic hormonal contraception. Swollen and inflamed units are called comedones.
-The propionibacterium acnes bacteria is felt to play an important role in acne. This is a bacteria that colonises the skin.
Describe management of acne vulgaris
-topical benzoyl peroxide
-topical retinoids- slow production of sebum
-topical antibiotics such as clindamycin
-oral antibiotics such as lymecycline
-oral contraceptive pill
-oral retinoids e.g. isotretinoin - last-line
-Co-cyprindiol (Dianette) is the most effect OCP- higher risk of thromboembolism
What are the side effects or isotretinoin?
-dry skin and lips
-photosensitivity of skin
-depression, anxiety, aggression and suicidal ideation
-rarely Stevens-Johnson syndrome and toxic epidermal necrolysis
What are viral exanthemas?
-an exanthem is an eruptive widespread rash
-originally there were six “viral exanthemas” known as first, second, third, fourth, fifth and sixth disease:
1- Measles
2- Scarlet fever
3-Rubella (aka German measles)
4- Dukes’ disease
5- Parvovirus B19
6- Roseola infantum
Describe the rash associated with Measles
-Koplik spots- greyish white spots on the buccal mucosa
-rash starts on the face, classically behind the eyes
-erythematous, macular rash with flat lesions
Describe the rash associated with Scarlet fever
-a red-pink, blotchy, macular rash with rough “sandpaper” skin that starts on the trunk and spreads outwards
-red, flushed cheeks
Describe a Rubella rash
-milder erythematous macular (flat reddened area of skin) rash compared with measles
-starts on face and spreads to rest of body
Describe the rash in Parvovirus B19
-bright red rash on both cheeks- slapped cheeks
What is the rash like in Roseola Infantum?
-a mild erythematous macular rash across the arms, legs, trunk and face and is not itchy
What are pressure ulcers?
-an injury that breaks down the skin and underlying tissue
-aka bed sores or pressure sores
How do pressure ulcers develop?
-when a large amount of pressure is applied to an area of skin over a short period to time
-the extra pressure disrupts the flow of blood through the skin
-without a blood supply, the affected skin becomes starved of oxygen and nutrients and begins to break down, leading to an ulcer forming
Risk factors of pressure ulcers
-patients confined to lying in a bed or sitting for prolonged periods of time
-type 2 diabetes
-over 70 years old
What are cutaneous warts?
Cutaneous warts are small, rough growths that are caused by infection of keratinocytes with human papilloma virus (HPV)
What is a verruca?
-aka plantar wart
-a wart on the sole of the foot
Describe treatment for warts
-cutaneous warts do not usually cause symptoms and in most cases resolve spontaneously within months, or, at the most, within 2 years
-cyrotherapy
-topical salicylic acid
What does pruritis mean?
Itching
What is the first-line treatment for patients with rosacea with mild papules and/or pustules
Topical ivermectin
(What is sarcoidosis?)
(-sarcoidosis is a chronic granulomatous disorder
-granulomas are inflammatory nodules full of macrophages
-the cause of these granulomas is unknown
-it is usually associated with respiratory symptoms but has many extra-pulmonary manifestations, such as erythema nodosum and lymphadenopathy
-symptoms can vary dramatically from asymptomatic to severe or life-threatening)
What is the single most important factor in determining prognosis of patients with malignant melanoma?
The invasion depth of a tumour (Breslow depth)
What is Breslow thickness?
The measurement of the depth of the melanoma from the surface of your skin down through to the deepest point of the tumour
What is the Clark scale?
The Clark scale is a way of measuring how deeply the melanoma has grown into the skin and which levels of the skin are affected.
What does dactylitis mean?
Inflammation of a digit (finger or toe)
What does onycholysis mean?
Detachment of the nail from the nail bed
What is the treatment for eczema herpeticum?
IV antivirals e.g. aciclovir
What is eczema herpeticum?
Eczema herpeticum describes a severe primary infection of the skin by herpes simplex virus 1 or 2
-it is more commonly seen in children with atopic eczema and often presents as a rapidly progressing painful rash
What does maculopapular mean?
A rash with both flat and raised parts
What does macule and papule mean?
macule=flat, reddened area of skin
papule=raised area of skin
What is the treatment for shingles
-oral aciclovir (antiviral)
What does umbilication mean?
A depression resembling a navel
What type of hypersensitivity reaction is allergic contact dermatitis?
Type IV hypersensitivity
What is Nikolsky sign?
Blisters and erosions appear when the skin is rubbed gently.
This sign is nearly always present in SJS and toxic epidermal necrolysis (TEN).
What is polymorphic eruption of pregnancy?
An itchy, bumpy rash that starts in the stretch marks of the abdomen in the last 3 months of pregnancy then clears with delivery.
What is post-herpetic neuralgia?
A lasting pain in the areas of your skin where you had shingles
What is impetigo?
-Impetigo is a superficial bacterial skin infection usually caused by either Staphylococcus aureus or Staphylococcus pyogenes.
-It can be a primary skin infection or a complication of an existing skin condition such as eczema, scabies or insect bites.
-Impetigo is common in children, particularly during warm weather.
What are the features of impetigo?
-‘golden’, crusted skin lesions typically found around the mouth
-very contagious
What is the management of impetigo?
-hydrogen peroxide 1% cream (for people who are not systemically unwell or at a high risk of complications)
-topical antibiotic creams- topical fusidic acid
-extensive disease-> oral flucloxacillin, oral erythromycin if penicillin-allergic
What is panniculitis?
Panniculitis refers to a group of conditions that involve inflammation of subcutaneous fat.
-despite having diverse causes, most forms of panniculitis have the same clinical appearance- the diagnosis is established by a skin biopsy
-the most common form of panniculitis is erythema nodosum
What is erythema nodosum?
-erythema nodosum is a type of panniculitis (inflammation of the subcutaneous fat)
-it presents as tender, erythematous nodules typically located on the anterior shins but can also appear on the forearms
-the condition may occur spontaneously or be associated with systemic diseases such as sarcoidosis, inflammatory bowel disease or streptococcal infection
Chronic plaque psoriasis management
-regular emollients
-a potent corticosteroid applied once daily plus vitamin D analogue (Calcipotriene) applied once daily
-coal tar preparation
-short-acting dithranol
-phototherapy
-photochemotherapy - psoralen + ultraviolet A light (PUVA)
Systemic therapy:
-oral methotrexate
-ciclosporin
-systemic retinoids
-biological agents: infliximab, etanercept and adalimumab
-ustekinumab
What are the most common types of skin cancer?
basal cell carcinoma
squamous cell carcinoma
melanoma
What is melanoma?
-Melanoma is a type of malignant cancer that arises from the melanocyte layer, normally situated in the basal layer of the epidermis
-Melanoma occurs when melanocytic stem cells undergo a genetic transformation and proliferate uncontrollably
What are melanocytes?
Melanocytes produce melanin, a protein that helps protect against harmful ultraviolet (UV) radiation exposure. Melanocytes are found in equal numbers in different skin tones. However, darker skin produces more melanin. Therefore, damage caused by UV exposure is more likely in white skin compared to brown or black skin.
When melanocytes grow in a non-cancerous way, they result in…
moles (benign melanocytic naevi) and freckles (lentigines and phelides)
What does In situ, invasive and metastatic mean?
-In situ= the tumour is confined to the epidermis
-invasive= the tumour has spread into the dermis
-metastatic= the tumour has spread to other tissues
Describe dermatitis herpetiformis
-an autoimmune blistering skin condition associated with coeliac disease
-it is caused by deposition of IgA in the dermis
-itchy, versicular skin lesions on extensor surfaces (elbows, knees, buttocks)
-management= gluten free diet and Dapsone (anti-infective)
Classic features of basal cell carcinoma
-slow growing
-flesh coloured or pink lesions with a pearly appearance
-rolled edges, central depression and presence of telangiectasia (dilated blood vessels)
Eczema treatment
Topicals: emollients, topical corticosteroids, protopic (tacrolimus)
Phototherapy
Systemic immunosuppression- Methotrexate (can affect liver and lungs), Ciclosporin (affect BP and kidneys)
Biologics
JAKS inhibitors
Topical steroid ladder
Mild: hydrocortisone 1%
Moderate: eumovate
Potent: betnovate 0.1%
Super potent: dermovate
Management of psoriasis
Topicals:
-emollients
-topical corticosteroids
-vitamin D analogues (Calcipotriene)
Phototherapy
Systemic immunosuppression:
-methotrexate
-ciclosporin
-acitretin
Biologics
Features of SCC
-keratotic, crusty
-on sun exposed sites
-grow quicker than BCC
-grow over a couple of months vs 6 months-1 year (in BCC)
Features of melanoma (ABCDE)
Asymmetrical
Border irregular
Colour (2+)
Diameter >6mm
Evolution
