Dermatology Flashcards
Define basal cell carcinoma.
Commonest form of skin malignancy, most commonly occurring on the face, that often invades surrounding tissue but seldom metastasizes.
- Also known as a rodent ulcer
What is Gorlin’s syndrome?
A condition that affects many areas of the body and increases the risk of developing various cancerous and noncancerous tumors.
- Strongly linked to basal cell carcinoma
What are the risk factors for basal cell carcinoma?
o Pprolonged sun exposure or UV radiation
o Photosensitising pitch
o Tar
o Arsenic
What are the presenting symptoms of basal cell carcinoma?
o A chronic slowly progressive skin lesion
o Usually found on the FACE but sometimes the scalp, ears or trunk
What are the types of basal cell carcinoma?
o Nodulo-ulcerative (most common)
o Morphoeic
o Superficial
o Pigmented
What are the signs of nodulo-ulcerative on examination?
o Small glistening translucent skin over a coloured papule
o Slowly enlarges
o Central ulcer with raised pearly edges
o Fine telangiectasia over the tumour surface
o Cystic change in larger lesions
What are the signs of morphoeic basal cell carcinoma on examination?
o Expanding, yellow/white waxy plaque with an ill-defined edge
o More aggressive than nodulo-ulcerative
What are the signs of superficial basal cell carcinoma on examination?
o Most often on trunk
o Multiple pink/brown scaly plaques with a fine edge expanding slowly
What are the signs of pigmented basal cell carcinoma on examination?
o Specks of brown or black pigment may be present in any BCC
What are the appropriate investigations for basal cell carcinoma?
o Diagnosis is mainly on clinical suspicion
o Biopsy is rarely necessary
Define contact dermatitis.
An inflammatory skin reaction in response to an external stimulus, acting either as an allergen or an irritant.
What are the two types of contact dermatitis?
o Allergic - a delayed type IV hypersensitivity reaction, which occurs after sensitisation and subsequent re-exposure to the allergen
- cosmetics, metals, topical medications, textiles
o Irritant - an inflammatory response that occurs after damage to the skin, usually by chemicals
- detergents/soaps, solvents, powders
What are the presenting symptoms of contact dermatitis?
o HANDS are the most frequently affected but can occur anywhere
o Redness of skin
o Vesicles and papules in the affected area
o Crusting and scaling of skin
o Itching of an affected area
o Fissures
o Hyperpigmentation
o Pain or burning sensation
o Make sure you do a thorough occupational history
What are the appropriate investigations for contact dermatitis?
o No investigations necessary most of the time
o Some may need patch testing
Define eczema.
A pruritic papulovesicular skin reaction to endogenous and exogenous agents.
What are the risk factors for eczema?
o Exogenous = irritants (e.g. nappy rash), contact (delayed type 4 hypersensitivity reaction to an allergen), atopic
o Endogenous = atopic, seborrhoeic, pompholyx (a type of eczema that affects the hands and feet), varicose veins, lichen simplex
What are the presenting symptoms of eczema?
Itching
Heat
Tenderness
Redness
Weeping
Crusting
Ask about occupational exposure to irritants (e.g. bleach)
Ask about personal/family history of atopy (e.g. asthma, hay fever)
What are the signs of acute eczema on examination?
Poorly demarcated erythematous oedematous dry scaling patches
Papules
Vesicles with exudation and crusting
Excoriation marks
What are the signs of chronic eczema on examination?
Thickened epidermis
Skin lichenification
Fissures
Change in pigmentation
What is the usually presentation of atopic eczema?
- mainly affects face and flexures
What is the usually presentation of seborrhoeic eczema?
o Yellow greasy scales on erythematous plaques
o Commonly found on eyebrows, scalp, presternal area
What is the usually presentation of pompholyx eczema?
o Vesiculobullous eruption on palms and soles
What is the usually presentation of nummular eczema?
o Coin shaped on the legs and trunk
What is the usually presentation of asteatotic eczema?
o Dry, crazy paring pattern
What are the appropriate investigation for eczema?
o Contact Eczema = skin patch testing - a disc containing allergens is diluted and applied on the skin for 48 hrs -> is positive if it causes a red raised lesion
o Atopic Eczema = lab testing e.g. IgE levels
Define erythema multiforme.
An acute hypersensitivity reaction of the skin and mucous membranes.
- Stevens-Johnson syndrome is a severe form with bullous lesions and necrotic ulcers.
What are precipitating factors for erythema multiforme?
o Drugs - e.g. sulphonamides, penicillin, phenytoin
o Infection - e.g. HSV, EBV, adenovirus, chlamydia, histoplasmosis
o Inflammatory - e.g. rheumatoid arthritis, SLE, sarcoidosis, ulcerative colitis
o Malignancy - e.g. lymphomas, leukaemia, myeloma
o Radiotherapy
What are the presenting symptoms of erythema multiforme?
Non-specific prodromal symptoms of upper respiratory tract infection
Sudden appearance of itching/burning/painful skin lesions
Skin lesions may fade leaving pigmentation
What are the signs of erythema multiforme on examination?
Classic target (bull’s eye) lesions with a rim of erythema surrounding a paler area
Vesicles/bullae
Urticarial plaques
Lesions are often symmetrical and distributed over the arms and legs including the palms, soles and extensor surfaces
How Stevens-Johnson syndrome characterised?
o Affecting > 2 mucous membranes - conjunctiva, cornea, lips, mouth, genitalia
o Systemic symptoms - sore throat, cough, fever, headache, myalgia, arthralgia, diarrhoea, vomiting
o Shock (hypotension and tachycardia)
What are the appropriate investigations for erythema multiforme?
o Usually unnecessary - erythema multiforme is very much a clinical diagnosis
o Bloods = high WC, eosinophils, ESR/CRP
o Imaging - excludes sarcoidosis and atypical pneumonia
o Skin biopsy - histology and direct immunofluorescence if in doubt about diagnosis
Define erythema nodosum.
Panniculitis (inflammation of subcutaneous fat tissue) presenting as red or violet subcutaneous nodules.
What are the presenting symptoms of erythema nodosum?
Tender red or violet nodules bilaterally on both shins
Occasionally on thighs or forearms
Fatigue
Fever
Anorexia
Weight loss
Arthralgia
Symptoms of underlying cause
What are the signs of erythema nodosum on examination?
Crops of red or violet dome-shaped nodules usually present on both shins
Occasionally appear on the thighs and forearms
Nodules are tender to palpation
Low-grade pyrexia
Joints may be tender and painful on movement
Signs of underlying CAUSE
What are the appropriate investigations for erythema nodosum?
o Determine underlying CAUSE
o Bloods = anti-streptolysin-O titres to check for streptococcal infection, FBC/CRP/ESR, U&Es, serum ACE (raised in sarcoidosis)
o Throat swab and cultures
o Mantoux/Head skin testing - for TB
o CXR - check for bilateral hilar lymphadenopathy or other evidence of TB, sarcoidosis or fungal infections
Define lipoma.
Slow-growing, benign adipose tumours that are most often found in the subcutaneous tissues.
What are the presenting symptoms and signs of lipoma?
Most are asymptomatic
Compression of nerves can cause pain
Soft or firm nodule
Smooth normal surface
Skin coloured
Most are < 5 cm in diameter
Mobile
Soft/doughy feel
What are the appropriate investigations for lipoma?
o Usually CLINICAL diagnosis
o US/MRI/CT used if there is doubt about the diagnosis
Define melanoma.
Malignancy arising from neoplastic transformation of melanocytes, the pigment-forming skin cells.
- Leading cause of death from skin disease.
What are the types of melanoma?
o Superficial spreading (70%)
o Nodular (15%)
o Lentigo maligna (10%)
o Acral lentiginous (5%)
Describe superficial spreading melanoma.
Usually arises in a pre-existing naevus, expands in a radial fashion before a vertical growth phase
Describe nodular melanoma.
Arises de novo
AGGRESSIVE
No radial growth phase
Describe lentigo malinga melanoma.
More common in elderly with sun damage
Large flat lesions
Progresses slowly
Usually on the face
Describe acral lentiginous melanoma.
Arise on palms, soles and subungual areas
Most common type in non-white populations
What are the presenting symptoms of melanoma?
Change in size, shape or colour of a pigmented skin lesion
Redness
Bleeding
Crusting
Ulceration
What are the signs of melanoma on examination?
What are the appropriate investigations for melanoma?
o Excisional Biopsy - histological diagnosis and determination of Clark’s Levels and Breslow Thickness
o Lymphoscintigraphy - a radioactive compound is injected into the lesion and images are taken over 30 mins to trace the lymph drainage and identify the sentinel nodes
o Sentinel Lymph Node Biopsy - check for metastatic involvement
o Staging - using ultrasound, CT or MRI, CXR
o Bloods - LFTs (because the liver is a common site of metastasis)
Define molluscum contagiosum.
A common skin infection caused by a pox virus that affects children and adults. Transmission is usually by direct skin contact.
What is the cause and what are the risk factors for molluscum contagiosum?
o Viral skin infection caused by molluscum contagiosum virus (MCV) - a type of pox virus
o Risk Factors = being a child, immunocompromised, atopic eczema
What are the presenting symptoms of molluscum contagiosum?
o Incubation period: 2-8 weeks
o Usually Asymptomatic barring the papules
o May be tenderness, pruritus and eczema around the lesion
o Lesions last for around 8 months
What are the signs of molluscum contagiosum on examination?
o Firm, smooth, umbilicated papules
o Usually 2-5 mm in diameter
o In children - tends to occur on the trunk and the extremities
o In adults - tends to occur on the lower abdomen, genital area and inner thighs (suggesting sexual contact)
What are the appropriate investigations for molluscum contagiosum?
Usually a CLINICAL diagnosis
Dermatoscopy may be useful if there is doubt
Define pressure sore.
Damage to the skin, usually over a bony prominence, as a result of pressure.
What are the risk factors for pressure sores?
Immobility
Hospitalisation
Alzheimer’s disease
Diabetes
What are the presenting symptoms and signs for pressure sores?
o Occurs over bony prominences - most commonly the sacrum and heel
o Pressure scores can be staged from Stage 1-4
o Are very TENDER
o May become infected leading to fevers, erythema and foul smell
What are the appropriate investigations for pressure sores?
o Clinical diagnosis - no investigations necessary
o Waterlow Score is used to predict risk of pressure sores in patients
Define psoriasis.
A chronic inflammatory skin disease, which has characteristic lesions and may be complicated by arthritis.
What are the general risk factors for psoriasis?
o genetics
o environment
o drugs
What are the risk factors for guttate psoriasis?
o Streptococcal sore throat
What are the risk factors for palmoplantar psoriasis?
o Smoking
o Middle-aged women
o Autoimmune thyroid disease
What are the risk factors for generalised pustular psoriasis?
o Hypoparathyroidism
What are the presenting symptoms of psoriasis?
o Itching and occasionally tender skin
o Pinpoint bleeding with removing scales (Auspitz phenomenon)
o Skin lesions may develop at sites of trauma/scars (Koebner phenomenon)
What are the signs of nummular/discoid psoriasis on examination?
o symmetrical, well-demarcated erythematous plaques with silvery scales over extensor surfaces (knee, elbows, scalp, sacrum)
What are the signs of flexural psoriasis on examination?
o Less scaly plaques in axilla, groins, perianal and genital skin
What are the signs of guttate psoriasis on examination?
o Small drop-like lesions over the trunk and limbs
What are the signs of palmoplantar psoriasis on examination?
Erythematous plaques with pustules on palms and soles
What are the signs of generalised pustular psoriasis on examination?
o Pustules distributed over limbs and torso - very widespread
What are the general signs of psoriasis on examination?
o Nail signs = pitting, onycholysis, subungual hyperkeratosis
o Joint Signs = FIVE presentations of psoriatic arthritis
- Asymmetrical oligoarthritis
- Symmetrical polyarthritis
- Distal interphalangeal joint predominance
- Arthritis mutilans
- Psoriatic spondylitis
What are the appropriate investigations for psoriasis?
o Most patients don’t need investigations
o Guttate psoriasis - anti-streptolysin-O titre, throat swab
o Flexural psoriasis - skin swabs to exclude candidiasis
o Nail clipping analysis for onychomycosis (fungal infection)
o Joint involvement analysed by checking for rheumatoid factor and radiographs
Define sebaceous cysts.
Epithelium-lined, keratinous, debris-filled cyst arising from a blocked hair follicle.
- Also known as an epidermal cyst.
What are the risk factors for sebaceous cysts?
o Gardner’s Syndrome = autosomal dominant condition characterised by the presence of multiple polyps in the colon and in extra-colonic sites (e.g. sebaceous cyst, thyroid cancer, fibroma)
What are the presenting symptoms of sebaceous cysts?
Non-tender slow-growing skin swelling
There are often multiple
Common on hair-bearing regions of the body (e.g. face, scalp, trunk or scrotum)
May become red, hot and tender if there is superimposed infection or inflammation
What are the signs of sebaceous cysts on examination?
Smooth tethered lump
Overlying skin punctum
May discharge granular creamy material that smells bad
What are the appropriate investigations for sebaceous cysts?
o None needed
o Skin biopsy or FNA may be used to rule out other differentials
What is the treatment for sebaceous cysts?
o Conservative = may be left alone if its not causing the patient any distress
o Surgical = excision of the cyst under local anaesthesia
o Medical = antibiotics if there is an infection
What are the possible complications of sebaceous cysts?
o Infection
o Abscess formation
o Recurrence (if incomplete excision)
o May ulcerate
Define squamous cell carcinoma.
Malignancy of epidermal keratinocytes of the skin.
Define Marjolin’s ulcer.
Squamous cell carcinoma that arises in an area of chronically inflamed skin.
What are the risk factors for squamous cell carcinoma?
o Main risk factor = UV RADIATION - sun exposure can lead to actinic keratosis (sun-induced precancerous lesion)
o Radiation
o Carcinogens (e.g. tar derivatives, cigarette smoke)
o Chronic skin disease (e.g. lupus)
o HPV
o Long-term immunosuppression
o Defects in DNA repair (xeroderma pigmentosum)
What are the presenting symptoms of squamous cell carcinoma?
Skin lesion
Ulcerated
Recurrent bleeding
Non-healing
What are the signs of squamous cell carcinoma on examination?
o Variable appearance - may be ulcerated, hyperkeratotic, crusted or scaly, non-healing
o Often on sun-exposed areas
o Palpate for local lymphadenopathy
What are the appropriate investigations of squamous cell carcinoma?
o Skin biopsy - confirm malignancy and specific type
o Fine-needle aspiration or lymph node biopsy - if metastasis is suspected
o Staging - using CT, MRI or PET
Define urticaria.
Itchy, red, blotchy rash resulting from swelling of the superficial part of the skin.
What occurs in deep tissues are involved in urticaria?
- Angiooedema occurs when the deep tissues, the lower dermis and subcutaneous tissues are involved and become swollen
What are the triggers of urticaria?
o Acute urticaria
- allergies (foods, bites, stings)
- viral infections
- skin contact with chemicals
- physical stimuli
o Chronic urticaria
- chronic spontaneous urticaria - medication, stress, infections
- autoimmune
What are the presenting symptoms and signs for urticaria?
o Central itchy white papule or plaque surrounded by erythematous flare
o Lesions vary in size and shape
o May be associated with swelling of the soft-tissues of the eyelids, lips and tongue (angiooedema)
o Individual lesions are usually transient
o Timescales: acute = symptoms develop quickly but normally resolve within 48 hrs but chronic = rash persists for > 6 weeks
What are the appropriate investigations for urticaria?
o Usually clinical
- Tests may be required for chronic urticaria (e.g. FBC, ESR/CRP, patch testing, IgE tests)
