Dermatology Flashcards
What is actinic keratosis?
Actinic, or solar, keratoses (AK) is a common premalignant skin lesion that develops as a consequence of chronic sun exposure
Features of actinic keratosis?
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
Mx of actinic keratosis
prevention of further risk: e.g. sun avoidance, sun cream
fluorouracil cream: typically a 2 to 3 week course. The skin will become red and inflamed - sometimes topical hydrocortisone is given following fluorouracil to help settle the inflammation
topical diclofenac: may be used for mild AKs. Moderate efficacy but much fewer side-effects
topical imiquimod: trials have shown good efficacy
cryotherapy
curettage and cautery
Features of Acne Rosacea
Features typically affects nose, cheeks and forehead flushing is often first symptom telangiectasia are common later develops into persistent erythema with papules and pustules rhinophyma ocular involvement: blepharitis sunlight may exacerbate symptoms/
Mx of Acne Rosacea
Management
Mild - topical metronidazole
Flushing without telangiectasia - topical brimonidine gel
severe - systemic antibiotics e.g. Oxytetracycline
Also:
-daily high-factor sunscreen
- camouflage creams
- laser therapy for prominent telangiectasia
- rhinophyma should be referred to dermatology
Mx of hyperhidrosis
topical aluminium chloride first-line. Main side effect is skin irritation
iontophoresis: particularly useful for patients with palmar, plantar and axillary hyperhidrosis
botulinum toxin: currently licensed for axillary symptoms
surgery: e.g. Endoscopic transthoracic sympathectomy. Patients should be made aware of the risk of compensatory sweating
What are Cherry Hemangiomas?
Features x4
Cherry haemangiomas (Campbell de Morgan spots) are benign skin lesions which contain an abnormal proliferation of capillaries. They are more common with advancing age and affect men and women equally. erythematous, papular lesions typically 1-3 mm in size non-blanching not found on the mucous membranes
What is piteous rosacea?
a self-limiting condition flowing viral infection in teenagers and young people.
Features include:
initial herald patch followed by more patches on the trunk
erythematous plaques with scaley edges
no treatment unless itchy, then consider antihistamines or topical steroids.
What is alopecia areata?
Outcomes
Mx options
presumed autoimmune condition causing localised, well-demarcated patches of hair loss. At the edge of the hair loss, there may be small, broken ‘exclamation mark’ hairs
Hair will regrow in 50% of patients by 1 year, and in 80-90% eventually. Careful explanation is therefore sufficient in many patients. Other treatment options include: topical or intralesional corticosteroids topical minoxidil phototherapy dithranol contact immunotherapy wigs
what are Curlings ulcers?
Stress ulcers in burns patients are referred to as Curlings ulcers and may cause haematemesis.
What is Erythema Nodosum?
inflammation of subcutaneous fat
typically causes tender, erythematous, nodular lesions
usually occurs over shins, may also occur elsewhere (e.g. forearms, thighs)
usually resolves within 6 weeks
lesions heal without scarring
What causes erythema nodosum?
infection: streptococci, tuberculosis, brucellosis
systemic disease: sarcoidosis, inflammatory bowel disease, Behcet’s
malignancy/lymphoma
drugs: penicillins, sulphonamides, combined oral contraceptive pill
pregnancy
What is guttate psoriasis?
Guttate psoriasis is more common in children and adolescents. It may be precipitated by a streptococcal infection 2-4 weeks prior to the lesions appearing.
Features
tear drop papules on the trunk and limbs
Mx of guttate psoriasis
most cases resolve spontaneously within 2-3 months
there is no firm evidence to support the use of antibiotics to eradicate streptococcal infection
topical agents as per psoriasis
UVB phototherapy
tonsillectomy may be necessary with recurrent episodes
What is Hereditary haemorrhagic telangiectasia?
Dx criteria.
autosomal dominant condition characterised by (as the name suggests) multiple telangiectasia over the skin and mucous membranes. Twenty percent of cases occur spontaneously without prior family history.
Definite diagnosis if 3 of:
epistaxis : spontaneous, recurrent nosebleeds
telangiectases: multiple at characteristic sites (lips, oral cavity, fingers, nose)
visceral lesions: for example gastrointestinal telangiectasia (with or without bleeding), pulmonary arteriovenous malformations (AVM), hepatic AVM, cerebral AVM, spinal AVM
family history: a first-degree relative with HHT
What is Kaposi’s Sarcoma
Tumour of vascular and lymphatic endothelium.
Purple cutaneous nodules.
Associated with immuno supression.
Classical form affects elderly males and is slow growing.
Immunosupression form is much more aggressive and tends to affect those with HIV related disease.
What is dermatitis herpitiformis
Chronic itchy clusters of blisters.
Linked to underlying gluten enteropathy (coeliac disease).
What is a dermatofibroma
Benign lesion.
Firm elevated nodules.
Usually history of trauma.
Lesion consists of histiocytes, blood vessels and fibrotic changes.
What is a pyogenic granuloma
Overgrowth of blood vessels.
Red nodules.
Usually follow trauma.
May mimic amelanotic melanoma.
What is acanthosis nigrans?
Brown to black, poorly defined, velvety hyperpigmentation of the skin.
Usually found in body folds
The most common cause is insulin resistance, which leads to increased circulating insulin levels. Insulin spillover into the skin results in its abnormal increase in growth (hyperplasia of the skin).
In the context of a malignant disease, acanthosis nigricans is a paraneoplastic syndrome and is then commonly referred to as acanthosis nigricans maligna. Involvement of mucous membranes is rare and suggests a coexisting malignant condition.
What is Lichen Sclerosis key features diagnosis management risks
Lichen sclerosus is an inflammatory condition which usually affects the genitalia and is more common in elderly females. Lichen sclerosus leads to atrophy of the epidermis with white plaques forming
itch is prominent
The diagnosis is usually made on clinical grounds but a biopsy may be performed if atypical features are present*
topical steroids and emollients
increased risk of vulval cancer
Features of impetigo
Features
‘golden’, crusted skin lesions typically found around the mouth
very contagious
Mx of impetigo
Limited, localised disease
topical fusidic acid
topical retapamulin is used second-line if fusidic acid has been ineffective or is not tolerated
Extensive disease
oral flucloxacillin or erythromycin if penicillin-allergic
children should be excluded from school until the lesions are crusted and healed or 48 hours after commencing antibiotic treatment
Subtypes of malignant melanoma
Superficial spreading - most common, limbs and torso of young people, a growing mole
Nodular - 2nd most common, sun-exposed skin in middle-aged people, red or black lump which may bleed or oozes
Lentigo maligna - uncommon, older people, a growing mole in a sun-exposed area
Acral lentiginous - rare, nails palms or soles. more common in African Americans or asians, subungual pigmentation.
What is vitiligo?
Features
Vitiligo is an autoimmune condition which results in depigmentation of the skin. It is thought to affect around 1% of the population and symptoms typically develop by the age of 20-30 years.
Features
well-demarcated patches of depigmented skin
the peripheries tend to be most affected
trauma may precipitate new lesions (Koebner phenomenon)
Associated conditions of vitiligo (5)
type 1 diabetes mellitus Addison's disease autoimmune thyroid disorders pernicious anaemia alopecia areata
Mx of vitiligo
sunblock for affected areas of skin
camouflage make-up
topical corticosteroids may reverse the changes if applied early
there may also be a role for topical tacrolimus and phototherapy, although caution needs to be exercised with light-skinned patients
Risk factors for squamous cell carcinoma (7)
excessive exposure to sunlight / psoralen UVA therapy
actinic keratoses and Bowen’s disease
immunosuppression e.g. following renal transplant, HIV
smoking
long-standing leg ulcers (Marjolin’s ulcer)
genetic conditions e.g. xeroderma pigmentosum, oculocutaneous albinism
Mx of squamous cell carcinoma
Surgical excision with 4mm margins if lesion <20mm in diameter. If tumour >20mm then margins should be 6mm. Mohs micrographic surgery may be used in high-risk patients and in cosmetically important sites.
location of venous ulceration
Mx of venous ulceration
Most commonly superior to the medial malleolus
compression bandaging, usually four layer (only treatment shown to be of real benefit)
oral pentoxifylline, a peripheral vasodilator, improves healing rate
Features of pyoderma gangrenosum
typically on the lower limbs
initially small red papule
later deep, red, necrotic ulcers with a violaceous border
may be accompanied systemic symptoms e.g. Fever, myalgia
Casues of pyoderma gangrenosum
idiopathic in 50% inflammatory bowel disease: ulcerative colitis, Crohn's rheumatoid arthritis, SLE myeloproliferative disorders lymphoma, myeloid leukaemias monoclonal gammopathy (IgA) primary biliary cirrhosis
Mx of pyoderma gangrenosum
oral steroids
ciclosporin and infliximab in difficult cases
classification of acne vulgaris
mild: open and closed comedones with or without sparse inflammatory lesions
moderate acne: widespread non-inflammatory lesions and numerous papules and pustules
severe acne: extensive inflammatory lesions, which may include nodules, pitting, and scarring
Mx of acne vulgaris
1) single topical therapy (topical retinoids, benzoyl peroxide)
2) dual topical combination therapy (topical antibiotic, benzoyl peroxide, topical retinoid)
3) oral antibiotics + topical therapy
4) combined oral contraceptives (COCP) + topical agent
5) oral isotretinoin: under specialist supervision
pregnancy is a contraindication to topical and oral retinoid treatment
What is seborrhoeic dermatitis?
Features
associated conditions (2)
Chronic dermatitis caused by an inflammatory reaction related to a proliferation of a normal skin inhabitant, a fungus called Malassezia furfur. common.
Features
eczematous lesions on the sebum-rich areas: scalp (may cause dandruff), periorbital, auricular and nasolabial folds
otitis externa and blepharitis may develop
parkinsons, HIV
Mx of Seborrhoeic dermatitis
Scalp disease management
over the counter preparations containing zinc pyrithione (‘Head & Shoulders’) and tar (‘Neutrogena T/Gel’) are first-line
the preferred second-line agent is ketoconazole
Face and body management
topical antifungals: e.g. ketoconazole
topical steroids: best used for short periods
difficult to treat - recurrences are common
which bacteria contributes to the development of acne?
Propionibacterium acnes
What is Molluscum contagiosum?
What does it look like?
A common skin infection caused by molluscum contagiosum virus (MCV). Transmission occurs directly by close personal contact, or indirectly via fomites (contaminated surfaces) such as shared towels and flannels. The majority of cases occur in children (often in children with atopic eczema), with the maximum incidence in preschool children aged 1-4 years.
Typically presents with characteristic pinkish or pearly white papules with a central umbilication, which are up to 5 mm in diameter. Lesions appear in clusters in areas anywhere on the body (except the palms of the hands and the soles of the feet).
Mx of Molluscum contagiosum?
Reassurance as self-limiting, doesn’t need treatment.
Spontaneous resolution usually occurs within 18 months
Hygiene advice as contagious:
- avoid sharing towels, clothing, and baths with uninfected people (e.g. siblings)
- not to scratch the lesions. If it is problematic, consider treatment to alleviate the itch
- Exclusion from school, gym, or swimming is not necessary
When to refer molluscum contagiousum
- HIV-positive with extensive lesions urgent referral to a HIV specialist
- For people with eyelid-margin or ocular lesions and associated red eye urgent referral to an ophthalmologist
- Adults with anogenital lesions should be referred to genito-urinary medicine, for screening for other sexually transmitted infections
Exacerbating facotrs for psoriasis
trauma
alcohol
drugs: beta blockers, lithium, antimalarials (chloroquine and hydroxychloroquine), NSAIDs and ACE inhibitors, infliximab
withdrawal of systemic steroids
