Dermatology Flashcards
1
Q
Learning objectives
A
Answer
2
Q
Define basal cell carcinoma
A
• COMMONEST form of skin malignancy, also known as a rodent ulcer
3
Q
Explain the aetiology / risk factors of basal cell carcinoma
A
- MAIN RISK FACTOR: prolonged sun exposure or UV radiation
- Seen in Gorlin’s syndrome
Other risk factors:
o Photosensitising pitch
o Tar
o Arsenic
4
Q
Summarise the epidemiology of basal cell carcinoma
A
- COMMON in those with FAIR SKIN
- Common in areas of high sunlight exposure
- Common in the elderly
- Rare before the age of 40 yrs
- Lifetime risk in Caucasians = 1 in 3
5
Q
Recognise the presenting symptoms of basal cell carcinoma
A
• A chronic slowly progressive skin lesion • Usually found on the: o FACE o Scalp o Ears o Trunk
6
Q
Recognise the signs of basal cell carcinoma on physical examination
A
Nodulo-ulcerative (MOST COMMON)
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
Morphoeic
o Expanding
o Yellow/white waxy plaque with an ill-defined edge
o More aggressive than nodulo-ulcerative
Superficial
o Most often on trunk
o Multiple pink/brown scaly plaques with a fine edge expanding slowly
Pigmented
o Specks of brown or black pigment may be present in any BCC
7
Q
Identify appropriate investigations for basal cell carcinoma and interpret the results
A
- Biopsy is RARELY necessary
* Diagnosis is mainly on clinical suspicion
8
Q
Define burns injury
A
When tissue damage occurs by thermal, electrical or chemical injury
9
Q
Explain the aetiology / risk factors of burns injury
A
• Contact with hot objects (lol) • Electricity • UV light • Irradiation • Chemicals High Risk Patients o Young children o Elderly
10
Q
Summarise the epidemiology of burns injury
A
UK has > 12,000 admission per year
11
Q
Recognise the presenting symptoms of burns injury
A
Note the circumstances of the burn
Important to find out the time, temperature and length of contact with the agent
Consider risk of smoke inhalation and carbon monoxide poisoning
12
Q
Recognise the signs of burns injury on physical examination
A
Check for inhalational injury or airway compromise:
o Stridor
o Dyspnoea
o Hoarse voice
o Soot in nose
o Singed nose hairs
o Carbonaceous sputum
Check site, depth and distribution of burn
Partial Thickness Burn
o Subdivided into:
Superficial: red and oedematous skin + PAINFUL
Heals within around 7 days with peeling of dead skin
Deep: blistering and mottling + PAINFUL
Heals over 3 weeks, usually without scarring
Full Thickness Burn
o Destruction of the epidermis and dermis
o Charred leathery eschars
o Firm and PAINLESS with loss of sensation
o Healing will occur by scarring or contractures and requires skin grafting
• Size of Burn
o Described as a percentage of body surface area
13
Q
Identify appropriate investigations for burns injury and interpret the results
A
Bloods o Oxygen saturation, ABG and carboxyhaemoglobin (if inhalational injury) o FBC o U&Es o Group and Save Investigations for electrical burns o Serum CK o Urine myoglobin (check for muscle damage) o ECG
14
Q
Define candidiasis
A
• Infection caused by Candida.
15
Q
Explain the aetiology/risk factors of candidiasis
A
- Caused by 15 different Candida species
- Candida albicans is the MOST COMMON cause of candidiasis in humans
Main types of candidiasis: o Oral candidiasis o Oesophageal candidiasis o Candidal vulvovaginitis o Candidal skin infections o Invasive candidal infections
Risk Factors o Broad-spectrum antibiotics o Immunocompromise (e.g. HIV, corticosteroids) o Central venous lines o Cushing's disease o Diabetes mellitus o GI tract surgery
16
Q
Summarise the epidemiology of candidiasis
A
- 60% of the healthy adult population are carriers
- Candidiasis occurs in over 80% of people with HIV
- Candida is one of the most common causes of invasive fungal infections in the Western world
17
Q
Recognise the presenting symptoms and signs of candidiasis
A
• Oral Candidiasis
o Oral Thrush (pseudomembranous oral candidiasis) - curd-like white patches in the mouth, which can be removed easily revealing an underlying red base. Most common in neonates
o There are lots of subtypes of oral candidiasis with slightly different features but the main features are: redness of the tongue and mouth, white plaques
• Oesophageal Candidiasis
o Dysphagia
o Pain on swallowing food or fluids
o It is an AIDS-defining illness
• Candidal Skin Infections
o Soreness and itching
o Skin appearance can be variable
o Red, moist skin area with ragged, peeling edge and possibly papules and pustules
18
Q
Identify appropriate investigations for candidiasis
A
- Oral Candidiasis - swabs and cultures are not particularly useful because a lot of normal people have candida in their mouth
- Swabs may be relevant to check for drug-resistance
- Therapeutic trials of antifungal (e.g. fluconazole) can help with diagnosis
- Oesophageal Candidiasis: definitive diagnosis is by endoscopy
- Invasive Candidiasis: blood cultures required if candidaemia is possible
19
Q
Define cellulitis
A
• Acute non-purulent spreading infection of the subcutaneous tissue, causing overlying skin inflammation
20
Q
Explain the aetiology/risk factors of cellulitis
A
• Often results from: o Penetrating injury o Local lesions (e.g. insect bits) o Fissuring (e.g. anal fissures) • These allow pathogenic bacteria to enter the skin • Most common organisms o Streptococcus pyogenes o Staphylococcus aureus o NOTE: beware of MRSA • Cellulitis of the orbit (orbital cellulitis) is usually caused by Haemophilus influenzae • Risk Factors o Skin break o Poor hygiene o Poor vascularisation of tissue (e.g. due to diabetes mellitus)
21
Q
Summarise the epidemiology of cellulitis
A
• VERY COMMON
22
Q
Recognise the presenting symptoms of cellulitis
A
- History of cut, scratch or injury
- Periorbital Cellulitis - painful swollen red skin around the eye
• Orbital Cellulitis - painful or limited eye movements, visual impairment
23
Q
Recognise the signs of cellulitis on physical examination
A
• Lesion o Erythema o Oedema o Warm tender indistinct margins o Pyrexia - may suggest systemic spread • NOTE: exclude the presence of an abscess (aspirate if pus suspected) • Periorbital o Swollen eye lids o Conjunctival infection • Orbital Cellulitis o Proptosis o Impaired visual acuity and eye movements o Test for RAPD , visual acuity and colour vision
24
Q
Identify appropriate investigations for cellulitis
A
- Bloods - WCC, blood culture
- Discharge - sample and send for MC&S
- Aspiration (if pus is suspected)
- CT/MRI - if orbital cellulitis is suspected (helps assess posterior spread of infection)
25
Generate a management plan for cellulitis
• Medical
o Oral penicillins (e.g. flucloxacillin) or tetracyclines are effective
o If hospital-acquired - treat empirically based on local guidelines and change depending on the sensitivity of cultured organisms
• Surgical
o Orbital decompression may be needed in orbital cellulitis (EMERGENCY)
• Abscess
o Aspirate
o Incision and drainage
o Excised completely
26
Identify possible complications of cellulitis
* Sloughing of overlying skin
* Orbital cellulitis - may cause permanent loss of vision, spread to the brain, abscess formation, meningitis, cavernous sinus thrombosis
27
Summarise the prognosis for patients with cellulitis
• Good prognosis
28
Define eczema
• A pruritic papulovesicular skin reaction to endogenous and exogenous agents
29
Explain the aetiology/risk factors of eczema
• There are lots of types because there are many different triggers
• Exogenous
o Irritants (e.g. nappy rash)
o Contact (delayed type 4 hypersensitivity reaction to an allergen)
o Atopic
• Endogenous
o Atopic
o Seborrhoeic
o Pompholyx (a type of eczema that affects the hands and feet)
o Varicose
o Lichen simplex
• Varicose - due to increased venous pressure in lower limbs
30
Summarise the epidemiology of eczema
* Contact - prevalence: 4%
| * Atopic - onset in first year of life, childhood incidence: 10-20%
31
Recognise the presenting symptoms of eczema
* Itching
* Heat
* Tenderness
* Redness
* Weeping
* Crusting
* Ask about occupational exposure to irritants 9eg.. Bleach)
* Ask about personal/family history of atopy (e.g. asthma, hay fever)
32
Recognise the signs of eczema on physical examination
```
• Acute
o Poorly demarcated erythematous oedematous dry scaling patches
o Papules
o Vesicles with exudation and crusting
o Excoriation marks
• Chronic
o Thickened epidermis
o Skin lichenification
o Fissures
o Change in pigmentation
• Based on type of eczema
o Atopic - mainly affects face and flexures
```
o Seborrhoeic - yellow greasy scales on erythematous plaques. Commonly found on eyebrows, scalp, presternal area
o Pompholyx - vesiculobullous eruption on palms and soles
o Varicose - associated with marked varicose veins
o Nummular - coin shaped, on legs and trunk
o Asteatotic - dry, crazy paring pattern
33
Identify appropriate investigations for eczema
• Contact Eczema
o Skin patch testing - a disc containing allergens is diluted and applied on the skin for 48 hrs. It is positive if it causes a red raised lesion
• Atopic Eczema
o Lab testing e.g. IgE levels
34
Define sebaceous cyst
• Epithelium-lined, keratinous, debris-filled cyst arising from a blocked hair follicle. Also known as an epidermal cyst.
35
Explain the aetiology/risk factors of sebaceous cysts
• Occlusion of the pilosebaceous gland
• Can be caused by traumatic insertion of epidermal elements into the dermis
• Embryonic remnants
• Risk Factors
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)
36
Summarise the epidemiology of sebaceous cysts
• VERY COMMON at any age
37
Recognise 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
38
Recognise the signs of sebaceous cysts on physical examination
* Smooth tethered lump
* Overlying skin punctum
* May discharge granular creamy material that smells bad
39
Identify appropriate investigations for sebaceous cysts
* NONE needed
| * Skin biopsy or FNA may be used to rule out other differentials
40
Generate a management plan for sebaceous cysts
• Conservative
o May be left alone if its not causing the patient any distress
• Surgical
o Excision of the cyst under local anaesthesia
• Medical
o Antibiotics if there is an infection
41
Identify possible complications of sebaceous cysts
* Infection
* Abscess formation
* Recurrence (if incomplete excision)
* May ulcerate
42
Summarise the prognosis for patients with sebaceous cysts
* EXCELLENT
| * Most do NOT require treatment
43
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
44
Explain the aetiology/risk factors of erythema multiforme
• Degeneration of basal epidermal cells
• Development of vesicles between cells in the basement membrane
• Lymphocytic infiltrate around the blood vessels and at the dermo-epidermal junction
• A precipitating factor is only identified 50% of the time
• Precipitating Factors:
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
45
Summarise the epidemiology of erythema multiforme
* Any age group
* Mainly in CHILDREN and YOUNG ADULTS
* TWICE as common in MALES
46
Recognise 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
47
Recognise the signs of erythema multiforme on physical 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
• Stevens-Johnson syndrome is characterised by:
o Affecting > 2 mucous membranes (e.g. conjunctiva, cornea, lips, mouth, genitalia)
o Systemic symptoms (e.g. sore throat, cough, fever, headache, myalgia, arthralgia, diarrhoea/vomiting)
o Shock (hypotension and tachycardia)
48
Identify appropriate investigations for erythema multiforme
• Usually unnecessary - erythema multiforme is very much a clinical diagnosis
• Bloods
o High WC, eosinophils, ESR/CRP
• Imaging - exclude sarcoidosis and atypical pneumonia
• Skin biopsy - histology and direct immunofluorescence if in doubt about diagnosis
49
Define erythema nodosum
• Panniculitis (inflammation of subcutaneous fat tissue) presenting as red or violet subcutaneous nodules
50
Explain the aetiology/risk factors of erythema nodosum
```
• Delayed hypersensitivity reaction to antigens associated with various infectious agents, drugs and diseases
• Infection
o Bacterial - e.g. streptococcus
o Viral - e.g. EBV
o Fungal - e.g. histoplasmosis
• Systemic Disease
o Sarcoidosis
o IBD
o Behcet's disease
• Malignancy
o Leukaemia
o Hodgkin's disease
• Drugs
o Sulphonamides
o Penicillin
o Oral contraceptive pills
• Pregnancy
• 25% of cases have no identifiable cause
```
51
Summarise the epidemiology of erythema nodosum
* Usually affects YOUNG ADULTS
| * THREE times more common in FEMALES
52
Recognise 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
53
Recognise the signs of erythema nodosum on clinical 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
54
Identify appropriate investigations for erythema nodosum
• Determine underlying CAUSE
• Bloods
o Anti-streptolysin-O titres (check for streptococcal infection)
o FBC/CRP/ESR - check for signs of infection/inflammation
o U&Es
o Serum ACE (raised in sarcoidosis)
• Throat swab and cultures
• Mantoux/Head skin testing - for TB
• CXR - check for bilateral hilar lymphadenopathy or other evidence of TB, sarcoidosis or fungal infections
55
Define herpes simplex
• Disease resulting from HSV1 or HSV2 infection
56
Explain the aetiology/risk factors of herpes simplex
• Transmitted via close contact (e.g. kissing, sexual intercourse) with an individual that is shedding the virus
• Pathophysiology
o After primary infection, the virus will become dormant (within nerve ganglia)
o Reactivation may occur in response to physical and emotional stresses or immunosuppression
o The virus causes cytolysis of infected epithelial cells leading to vesicle formation
57
Summarise the epidemiology of herpes simplex
* 90% of adults are seropositive for HSV1 by 30 yrs
* 35% of adults > 60 yrs are seropositive for HSV2
* More than 1/3 of the world population have recurrent HSV infections
58
Recognise the presenting symptoms of herpes simplex
• HSV1 - primary infection is often asymptomatic
• Possible symptoms of primary HSV1 infection:
o Pharyngitis
o Gingivostomatitis (eating might be painful)
o Herpetic whitlow (abscess at the end of the finger caused by infection with HSV - it is very painful)
• Symptoms of reactivation of HSV1:
o Prodrome of perioral tingling and burning
o Vesicles appear - they will ulcerate and crust over
o Complete healing within 8-10 days
• Symptoms of HSV2:
o Painful blisters and rash in the genital, perigenital and anal area
o Dysuria
o Fever
o Malaise
• Symptoms of HSV encephalitis:
o Usually caused by HSV1 so causes HSV1 type symptoms
• Symptoms of HSV keratoconjunctivitis
o Watering eyes
o Photophobia
59
Recognise the signs of herpes simplex on physical examination
• HSV1 Primary Infection
o Tender cervical lymphadenopathy
o Erythematous, oedematous pharynx
o Oral ulcers filled with yellow slough (gingivostomatitis)
```
o Herpetic whitlow
• Herpes Labialis (reactivation affecting the mouth)
o Perioral vesicles/ulcers/crusting
• HSV2
o Maculopapular rash
o Vesicles
o Ulcers
o All of these are found on the external genitalia, anal margin and upper thighs
o Others: inguinal lymphadenopathy, pyrexia
• HSV2 Encephalitis
o Signs of encephalitis
• HSV Keratoconjunctivitis
```
o Dendritic ulcer on the iris (better visualised with fluorescein)
60
Identify appropriate investigations for herpes simplex
* Diagnosis is usually CLINICAL
| * Vesicle fluid can be sampled and sent for electron microscopy, PCR
61
Define lipoma
• Slow-growing, benign adipose tumours that are most often found in the subcutaneous tissues.
62
Explain the aetiology/risk factors of lipoma
```
• Benign tumours of adipocytes
• Conditions associated with lipomas
o Familial multiple lipomatosis
o Gardner's syndrome
o Dercum's disease
o Madelung's disease
• Liposarcoma - rare malignant tumour of adipose tissue
```
63
Summarise the epidemiology of lipomas
* Can be seen at any age but more common between 40-60 yrs
| * Relatively COMMON
64
Recognise 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
65
Identify appropriate investigations for lipoma
* Usually CLINICAL diagnosis
| * US/MRI/CT used if there is doubt about the diagnosis
66
Define melanoma
• Malignancy arising from neoplastic transformation of melanocytes, the pigment-forming skin cells. The leading cause of death from skin disease.
67
Explain the aetiology/risk factors of melanoma
```
• DNA damage caused by ultraviolet radiation leads to neoplastic transformation
• 50% arise in existing naevi
• 50% arise in previously normal skin
• FOUR histopathological types
o Superficial Spreading (70%)
```
```
• Arises in a pre-existing naevus, expands in a radial fashion before a vertical growth phase
o Nodular (15%)
```
• Arises de novo
• AGGRESSIVE
• NO radial growth phase
o Lentigo Maligna (10%)
```
• More common in ELDERLY with sun damage
• Large flat lesions
• Progresses slowly
• Usually on the face
o Acral Lentiginous (5%)
```
* Arise on palms, soles and subungual areas
* Most common type in NON-WHITE populations
68
Summarise the epidemiology of melanoma
* Steadily increasing in incidence
| * WHITE races have 20 x increased risk compared to non-whites
69
Recognise the presenting symptoms of melanoma
* Change in size, shape or colour of a pigmented skin lesion
* Redness
* Bleeding
* Crusting
* Ulceration
70
Recognise the signs of melanoma on physical examination
```
ABCDE criteria for examining moles:
• A - asymmetry
• B - border irregularity
• C - colour variation
• D - diameter > 6 mm
• E - elevation/evolution
```
71
Identify appropriate investigations for melanoma
* Excisional Biopsy - histological diagnosis and determination of Clark's Levels and Breslow Thickness (two methods of determining the depth of penetration of a melanoma)
* 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
* Sentinel Lymph Node Biopsy - check for metastatic involvement
* Staging - using ultrasound, CT or MRI, CXR
* Bloods - LFTs (because the liver is a common site of metastasis)
72
Define molluscum contagiosum
• A common skin infection caused by a pox virus that affects children and adults. Transmission is usually by direct skin contact.
73
Explain the aetiology/risk factors of molluscum contagiosum
```
• Viral skin infection caused by molluscum contagiosum virus (MCV)
• It is a type of pox virus
• Risk Factors
o Mainly in CHILDREN
o Immunocompromised
o Atopic eczema
```
74
Summarise the epidemiology of molluscum contagiosum
* COMMON
* 90% of patients are < 15 yrs
* A lot of people will not seek medical attention for it
75
Recognise the presenting symptoms of molluscum contagiosum
* Incubation period: 2-8 weeks
* Usually ASYMPTOMATIC
* There may be tenderness, pruritus and eczema around the lesion
* Lesions last for around 8 months
76
Recognise the signs of molluscum contagiosum on physical examination
* Firm, smooth, umbilicated papules
* Usually 2-5 mm in diameter
* In children - tends to occur on the trunk and the extremities
* In adults - tends to occur on the lower abdomen, genital area and inner thighs (suggesting sexual contact)
77
Identify appropriate investigations for molluscum contagiosum
* Usually a CLINICAL diagnosis
| * Dermatoscopy may be useful if there is doubt
78
Define pressure sores
• Damage to the skin, usually over a bony prominence, as a result of pressure.
79
Explain the aetiology/risk factors of pressure sores
• Constant pressure limits blood flow to the skin leading to tissue damage
• They occur as a result of pressure, friction and shear
• Risk Factors
o IMMOBILITY
o Alzheimer's disease
o Diabetes
80
Summarise the epidemiology of pressure sores
* Very COMMON in hospitals
| * Most commonly occurs in the ELDERLY
81
Recognise the presenting symptoms and signs of pressure sores
* Occurs over bony prominences - most commonly the SACRUM and HEEL
* Pressure scores can be staged from Stage 1-4
* They are very TENDER
* They may become infected leading to fevers, erythema and foul smell
82
Identify appropriate investigations for pressure sores
* NO investigations necessary
* Clinical diagnosis
* Waterlow Score is used to predict risk of pressure sores in patients
83
Define psoriasis
• A chronic inflammatory skin disease, which has characteristic lesions and may be complicated by arthritis
84
Explain the aetiology/risk factors of psoriasis
• UNKNOWN
• Genetic, environmental factors and drugs are implicated
• Risk Factors
o Guttate psoriasis - streptococcal sore throat
o Palmoplantar psoriasis - smoking, middle-aged women, autoimmune thyroid disease
o Generalised pustular psoriasis - hypoparathyroidism
85
Summarise the epidemiology of psoriasis
* Affects 1-2% of population
| * Peak age of onset: 20 yrs
86
Recognise the presenting symptoms of psoriasis
* Itching and occasionally tender skin
* Pinpoint bleeding with removing scales (Auspitz phenomenon)
* Skin lesions may develop at sites of trauma/scars (Koebner phenomenon)
87
Recognise the signs of psoriasis on physical examination
* Discoid/Nummular psoriasis - symmetrical, well-demarcated erythematous plaques with silvery scales over extensor surfaces (knee, elbows, scalp, sacrum)
* Flexural psoriasis - less scaly plaques in axilla, groins, perianal and genital skin
* Guttate psoriasis - small drop-like lesions over trunk and limbs
* Palmoplantar psoriasis - erythematous plaques with pustules on palms and soles
* Generalised pustular psoriasis - pustules distributed over limbs and torso
* Nail Signs
```
o Pitting
o Onycholysis
o Subungual hyperkeratosis
• Joint Signs - FIVE presentations of psoriatic arthritis
o Asymmetrical oligoarthritis
o Symmetrical polyarthritis
o Distal interphalangeal joint predominance
o Arthritis mutilans
o Psoriatic spondylitis
```
88
Identify appropriate investigations for psoriasis
* Most patients DO NOT need investigations
* Guttate psoriasis -anti-streptolysin-O titre, throat swab
* Flexural psoriasis - skin swabs to exclude candidiasis
* Nail clipping analysis for onychomycosis (fungal infection)
* Joint involvement analysed by checking for rheumatoid factor and radiographs
89
Define squamous cell carcinoma
• Malignancy of epidermal keratinocytes of the skin.
| o Marjolin's ulcer is a squamous cell carcinoma that arises in an area of chronically inflamed skin
90
Explain the aetiology / risk factors of squamous cell carcinoma
* Main risk factor = UV RADIATION
* Sun exposure can lead to actinic keratosis (sun-induced precancerous lesion)
• Other risk factors:
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)
91
Summarise the epidemiology of squamous cell carcinoma
* SECOND most common cutaneous malignancy (20% of all skin cancers)
* Occurs mainly in MIDDLE-AGED and ELDERLY people
* LIGHT-SKINNED individuals are at higher risk
* 2-3 x more common in MALES
92
Recognise the presenting symptoms of squamous cell carcinoma
* Skin lesion
* Ulcerated
* Recurrent bleeding
* Non-healing
93
Recognise the signs of squamous cell carcinoma on physical examination
* Variable appearance - may be ulcerated, hyperkeratotic, crusted or scaly, non-healing
* Often on sun-exposed areas
* Palpate for local lymphadenopathy
94
Identify appropriate investigations for squamous cell carcinoma and interpret the results
* Skin Biopsy - confirm malignancy and specific type
* Fine-needle aspiration or lymph node biopsy - if metastasis is suspected
* Staging - using CT, MRI or PET
95
Define urticaria
• Itchy, red, blotchy rash resulting from swelling of the superficial part of the skin. Angiooedema occurs when the deep tissues, the lower dermis and subcutaneous tissues are involved and become swollen.
o AKA hives
96
Explain the aetiology/risk factors of urticaria
• Caused by activation of mast cells in the skin, resulting in the release of histamines
• The cytokine release leads to capillary leakage, which causes swelling of the skin and vasodilation --> erythematous appearance
• Possible Triggers:
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
97
Summarise the epidemiology of urticaria
* 15% of general population experience urticaria at some point in life
* Acute is much more common than chronic urticaria
98
Recognise the presenting symptoms and signs of urticaria
• Central itchy white papule or plaque surrounded by erythematous flare
• Lesions vary in size and shape
• May be associated with swelling of the soft-tissues of the eyelids, lips and tongue (angiooedema)
• Individual lesions are usually transient
• Timescales:
o Acute - symptoms develop quickly but normally resolve within 48 hrs
o Chronic - rash persists for > 6 weeks
99
Identify appropriate investigations for urticaria
* Usually clinical
| * Tests may be required for chronic urticaria (e.g. FBC, ESR/CRP, patch testing, IgE tests)
100
Define varicella zoster
• Primary infection is called varicella (chickenpox). Reactivation of the dormant virus (found in dorsal root ganglia), causes zoster (shingles).
o NOTE: varicella zoster is also known as herpes zoster
101
Explain the aetiology/risk factors of varicella zoster
* VZV is a herpes ds-DNA virus
* Highly contagious
* Transmission by aerosol inhalation or direct contact with vesicular secretions
102
Summarise the epidemiology of varicella zoster
* Chicken pox peak incidence: 4-10 yrs
* Shingles peak incidence: > 50 yrs
* 90% of adults are VZV IgG positive
103
Recognise the presenting symptoms of varicella zoster
• Chickenpox
o Prodromal malaise
o Mild pyrexia
o Sudden appearance of intensely itchy spreading rash mainly affecting face and trunk
o Vesicles weep and crust over
o New vesicles appear
o Contagious from 48 hrs before the rash until after the vesicles have all crusted over (7-10 days)
• Shingles
o May occur after a period of stress
o Tingling/hyperaesthesia in a dermatomal distribution
• Dermatomal because the rash remains dormant in the dorsal root ganglia and reactivation makes the virus travel down the sensory axon to produce a dermatomal shingles rash
o Painful skin lesions
o Recovery: 10-14 days
104
Recognise the signs of varicella zoster on physical examination
```
• Chickenpox
o Maculopapular rash
o Areas of weeping and crusting
o Skin excoriation (from scratching)
o Mild pyrexia
• Shingles
o Vesicular maculopapular rash
o Dermatomal distribution
o Skin excoriation
```
105
Identify appropriate investigations for varicella zoster
* Usually CLINICAL diagnoses
* Vesicle fluid may be sent for electron microscopy viral PCR (RARELY necessary)
* Chicken pox in an adult with previous history of varicella infection may require HIV testing
106
Generate a management plan for varicella zoster
```
• Chickenpox
o Children - treat symptoms
o Adults - consider aciclovir
• Shingles
o Aciclovir, valaciclovir, famciclovir
• Prevention
o Varicella Zoster Ig (VZIG) - may be considered in immunosuppressed or pregnant
```
107
Identify possible complications of varicella zoster
```
• Chickenpox
o Secondary infection
o Scarring
o Pneumonia
o Encephalitis
o Congenital varicella syndrome
• Shingles
o Postherpetic neuralgia
o Zoster ophthalmicus (rash in the ophthalmic division of the trigeminal nerve)
```
o Ramsay-Hunt syndrome
• DEFINITION: reactivation of VZV in the geniculate ganglion causing zoster of the ear and facial nerve palsy. Vesicles may be seen behind the pinna of the ear or in the ear canal
o Sacral zoster
o Motor zoster
108
Summarise the prognosis for patients with varicella zoster
* Depends on complications
| * Worse in pregnancy, elderly and immunocompromised
