Dermatology Flashcards
What is Basal cell carcinoma (BCC)
Slow growing locally invasive tumour of the basal cells of the epidermis - Rarely metastasizes
This is the most common form of skin malignancy also known as rodent ulcer
What are the risk factors for BCC
- Excessive UV radiation exposure
- Frequent/severe sunburn in childhood
Other
- Skin type 1 - Fitzpatrick skin types
- Older age
- Males
- Immunosuppression
- FHx or PMH of skin cancer
Where on the body are BCCs usually found
Face
Scalp
Ears
Trunk
What are the different types of BCC
Nodulo-ulcerative (Most common)
- Small glistening translucent skin over a coloured papule
- Slowly enlarges
- Central ulcer with raised pearly edges
- Fine telangiectasia over the tumour surface
- Cystic change in larger lesions
Morphoeic
- Expanding
- Yellow/white waxy plaque with an ill-defined edge
- More aggressive than nodulo-ulcerative
Superficial
- Most often on trunk
- Multiple pink/brown sclay plaques with a fine edge expanding slowly
Pigmented
- Specks of brown or black pigment may be present in any BCC
How is BCC diagnosed
It is diagnosed histologically through biopsy (Shave biopsy or punch biopsy)
Shave for cosmetically challenging
Routine referral
What is Squamous cell carcinoma (SCC)
Locally invasive malignant tumour of the epidermal keratinocytes or appendages, with potential to metastasise
What are the risk factors for SCC
- Excessive UV radiation exposure
- Premalignant skin conditions - Actinic keratoses - Crumbly yellow-white crusting
- Chronic inflammation - Leg ulcer, wound scar (Marjolin’s ulcer)
- Immunosuppression
- FHx or PMH of skin cancer
- 2nd most common - Middle aged and elderly
- Men
Where on the body are SCCs usually found
- Head & Neck - 84%
- Extensors upper limbs - 13%
How is SCC diagnosed
Biopsy
Staging - CT, MRI, PET
What is Melanoma
Invasive malignant tumour of the epidermal melanocytes which has the potential to metastasise
What are the risk factors for Melanoma
- Excessive UV radiation exposure
- Skin type 1 - Always burns, never tans
- History of multiple moles or atypical moles
- FHx or PMH of skin cancer
- Least common skin cancer
- Average age is 63 years can be younger
How does Melanoma present
Asymmetrical shape (2pts) Border irregularity Colour irregularity (2pts) Diameter 7mm or more (1pt) Evolution of lesion (Size) (2pts)
Symptoms:
- Inflammation (1pt)
- Oozing (1pt)
- Change in sensation (1pt)
(NICE 7 point checklist pt - Greater than 3 points 2 week wait referral)
Where do Melanomas usually present
Legs in women
Trunk in men
What are the different types of Melanoma
Superficial spreading (70%) - Arises in a pre-existing naevus, expands in a radial fashion before a vertical growth phase
Nodular (15%)
- Arises de novo
- Aggressive
- No radial growth
Lentigo maligna (10%)
- Elderly sun damaged
- Large flat lesion
- Progresses slowly
- Usually on the face
Acral lentiginous (5%)
- Arises on palms, soles and subungual areas
- Most common type in non-white populations
How is Melanoma investigated
- Examination with dermatoscope in secondary care
- Biopsy - Full thickness excisional biopsy - Definitive
- Atypical take pictures and compare months later
Sentinel lymph node biopsy
Staging - CT, MRI, CXR
What is Molluscum contagiosum
A common skin infection caused by a pox virus that affects children and adults
What are risk factors for Molluscum contagiosum
Viral skin infection - MCV a type of pox virus
- Transmitted via contact: Swimming pool, sexual contact
- HIV infection
- Atopic eczema
- Children 1-4
What are the signs and symptoms of Molluscum contagiosum
Incubation period of 2-8 weeks
Usually asymptomatic
Potential tenderness pruritus and eczema around lesion
Firm, smooth, pearly, umbilicated papule
2-5mm in diameter
Children: Trunk and extremities
Adults: Lower abdomen, genital area and inner thighs
How is Molluscum contagiosum diagnosed?
Clinical diagnosis
Potential HIV test
Biopsy rarely necessary
What are Pressure sores
Damage to the skin usually over a bony prominence as a result of pressure
What are causes of Pressure sores
Constant pressure limits blood flow to skin
- Immobility
- Alzheimer’s disease
- Diabetes
- Very common in hospitals
What are the signs and symptoms of Pressure sores
Over bony prominences - Most commonly Sacrum and heels
- Very tender
- They may be infected leading to fevers, redness and foul smell
Graded from 1-4
1 - Non-blanching redness of intact skin
2 - Partial thickness skin loss involving epidermis, dermis or both - Abrasion or blister
3 - Full thickness skin loss involving damage to or necrosis of subcutaneous tissue - Through to fascia
4 - Extensive destruction, tissue necrosis, or damage to muscle, bone or supporting structures
How is the risk of pressure sores in patients predicted
Using the Waterloo score
What is a Lipoma
Slow-growing, benign adipose tumour that are most often found in the subcutaneous tissues
What are causes of Lipomas
Benign tumours of adipocytes
Associated conditions:
- Familial multiple lipomatosis
- Gardner’s syndrome
- Dercum’s disease
- Madelung’s disease
Liposarcoma - Rare malignant tumour of adipose tissue
What are signs and symptoms of Lipomas
Most asymptomatic
Compression of nerves can cause pain Soft or firm nodule Smooth surface Skin coloured Most <5cm diameter Mobile
How are Lipomas diagnosed
US/MRI/CT used if any doubt
Core needle biopsy
Excisional - Bigger than 3cm
What is Eczema
An inflammatory skin condition characterised by dry, pruritic skin with chronic relapsing course
What are causes of Eczema
Exogenous:
- Irritants
- Contact
Endogenous:
- Atopic
- Seborrhoeic
- Pompholyx
- Varicose
- Lichen simplex
What are the symptoms of Eczema
Itching Heat Tenderness Dry Crusting Occupational exposure to irritant FHx or Hx of atopy
What are signs or Eczema
- Poorly demarcated erythematous oedematous dry scaling patches
- Papules
- Vesicles with exudation and crusting
- Excoriation marks
- Thickened epidermis
- Skin lichenification
- Fissures
- Change in pigmentation
What are the different types of Eczema
Atopic - Mainly affects face and flexures in children - Lichenification
Seborrhoeic - Yellow greasy scales on erythematous plaques. Commonly found on eyebrows, scalp, presternal area
Contact - Nickel or other allergens cause type 4 hypersensitivity
Dyshidrotic/Pompholyx - Vesiculobullous eruption on palms and soles
Discoid/Nummular - Coin shaped, on legs and trunk
Eczema herpeticum - HSV infection in eczema sufferer - Medical emergency
Varicose - Associated with marked varicose veins
Asteatotic - Dry, crazy paring pattern
How is Eczema diagnosed
Clinically usually
Skin prick - Contact eczema - a disc containing allergens is diluted and applied on the skin for 48hrs. It is positive if it causes a red raised lesion
IgE levels - Atopic
How is Herpes simplex virus contracted
It is transmitted via close contact (Kissing, sexual intercourse) with an individual that is shedding the virus
What are symptoms of Herpes simplex virus
Primary HSV-1:
- Pharyngitis
- Gingivostomatitis
- Herpetic whitlow
Reactivation HSV-1:
- Prodrome of perineal tingling and burning
- Vescile appear they will ulcerate and crust over
- Complete healing in 8-10 days
HSV-2:
- Painful blisters and rash in the genital, perigenital and anal area
- Dysuria
- Fever
- Malaise
HSV encephalitis:
- Usually caused by HSV-1 so causes HSV-1 type symptoms
HSV keratoconjunctivitis:
- Watering eyes
- Photophobia
What are signs of Herpes simplex virus
Primary HSV-1:
- Tender cervical lymphadenopathy
- Erythematous, oedematous pharynx
- Oral ulcers filled with yellow slough (gingivostomatitis)
- Herpetic whitlow
HSV-2:
- Maculopapular rash
- Vesicles
- Ulcers
- All of these are found on the external genitalia, anal margin and upper thighs
- Others: inguinal lymphadenopathy, pyrexia
HSV encephalitis:
- Signs of encephalitis
HSV keratoconjunctivitis:
- Dendritic ulcer on the iris (Better visualised by fluorescein)
How is Herpes simplex virus diagnosed
Usually clinical
Viral culture
What are the different types of Burns injury
Contact with hot object Electricity UV light Irradiation Chemicals
What are the different thicknesses of burns
Partial thickness burn
- Superficial: Red and oedematous skin + painful - Heals within around 7 days with peeling of dead skin
- Deep: Blistering and mottling + painful - Heal within over 3 weeks, usually without scarring
Full thickness burn: Destruction of the epidermis and dermis. Charred leathery eschars. Firm and painless with loss of sensation. Healing will occur by scarring or contractors and requires skin grafting
What other signs should be considered in burn victims
Signs of inhalational injury or airway compromise:
- Stridor
- Dyspnoea
- Hoarse voice
- Soot in nose
- Singed nose hairs
- Carbonaceous sputum
What are the investigative findings in Burn injuries
FBC - Low Ht, Hypovolaemia, Neutropenia, Thrombocytopenia
U&Es - Urea, Creatinine, Glucose, Hyponatraemia, Hypokalaemia
What are the main types of Candidiasis
Oral Oesophageal Candidal vulvovaginitis Candidal skin infections Invasic candidate infections
What are risk factors for Candidiasis
- Broad spectrum antibiotics
- Immunocompromise (HIV, Corticosteroids)
- Central venous lines
- Cushing’s disease
- DM
- GI tract surgery
What are signs and symptoms of Candidiasis
Oral thrush - Curd-like white patches in the mouth, which can be removed easily revealing an underlying red base
Oesophageal - Dysphagia, Odynophagia, It is an AIDS-defining illness
Candidal skin infections - Soreness and itching, skin appearance can be variable, red, moist skin area with ragged, peeling edge and possibly papule and pustules
How is Candidiasis diagnosed
Oral Candidiasis - Therapeutic trials of antifungal (-azole) can help diagnosis
Oesophageal - Endoscopy
Invasive - Blood cultures required if candidaemia is possible
What is a Sebaceous cysts
This is an epithelium-lined, keratinous, debris-filled cyst arising from a blocked hair follicle
What are signs and symptoms of Sebaceous cysts
- Non-tender slow growing skin swelling
- Often multiple
- Hair-bearing regions of the body
- May become infected and inflammed
- May discharge granular creamy material that smell bad
What is 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 causes of Erythema multiforme
50% idiopathic
Precipitating factors:
- Drugs: Sulphonamides, Penicillin, Phenytoin
- Infection: HSV, EBV, Adenovirus, Chlamydia, Histoplasmosis
- Inflammation: RA, SLE, Sarcoidosis, UC
- Malignancy: Lymphoma, Leukaemia, Myeloma
- Radiotherapy
Who is mainly affected by Erythema multiforme
Any age group
Mainly children and young adults
Twice as common in males
What are symptoms of Erythema multiforme
- Prodromal symptoms of URTI
- Sudden appearance of itching/burning/painful skin lesions
- Skin lesions may fade leaving pigmentation
What are signs of Erythema multiforme
- Classic target (bull’s eye) lesions with 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.
What is Stevens-‐Johnson
syndrome
This is a severe form of Erythema multiforme characterised by:
- Affecting 2 or more mucous membranes (Conjunctiva, Cornea, Lips, Mouth,Genitalia)
- Systemic symptoms (e.g Sore throat, Fever, Cough, Headache, Diarrhoea, Vomiting)
- Shock (Hypotension and tachycardia)
How is Erythema multiforme diagnosed
Usually clinical
Bloods - High WCC, Eosinophilia
ESR/CRP
Imaging - Exclude sarcoidosis and atypical pneumonia
Skin biopsy - Histology and direct immunofluorescence if in doubt about diagnosis
What is Erythema nodosum
Hypersensitivity reaction causing inflammation of subcutaneous fat tissue presenting as red or violet subcutaneous nodules
What are the causes of Erythema nodosum
Infection:
- Bacterial: Streptococcus
- Viral: EBV
- Fungal: Histoplasmosis
Systemic
- Sarcoidosis
- IBD
- Behcet’s disease
Malignancy
- Leukaemia
- Hodgkin’s disease
Drugs
- Sulphonamides
- Penicillin
- OCP
Pregnancy
25% of cases have no identifiable cause
Who is usually affected by Erythema nodosum
Young adults
3x in females
What are the signs and symptoms of Erythema nodosum
- Crops of red/violet dome shaped nodules usually present on both shins - Tender
- Occasionally on thighs or forearms
- Low grade fever
- Joints may be tender and painful on movement
How is Erythema nodosum investigated
Investigations are geared at determining the cause
Bloods: Anti-streptolysin-O titre FBC/CRP/ESR - Signs of infection/inflammation U&Es Serum ACE - Sarcoidosis
Throat swab and cultures
Mantoux/head skin testing - TB
CXR - Bilateral hilar lymphadenopathy or other evidence of TB, Sarcoidosis or fungal infection
What is Urticaria
Itchy, red, blotchy rash resulting from swelling of the superficial part of skin.
Angioedema occurs when the deep tissues, lower dermis and subcutaneous tissues are involved and become swollen
AKA Hives
What are causes of Urticaria
Acute Urticaria:
- Allergies
- Viral infections
- Skin contact with chemicals
- Physical stimuli
Chronic Urticaria:
- Chronic spontaneous urticaria
- Autoimmune
What are signs and symptoms of Urticaria
- Central itchy which 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
- Individual lesions are usually transient
Timescales:
- Acute: Symptoms develop quickly but normally resolve within 48 hrs
- Chronic: Rash persists for >6 weeks
How is Urticaria diagnosed
Usually clinical
Tests may include (FBC, ESR/CRP, path testing, IgE tests)
What is Psoriasis
Chronic inflammatory skin disease due to hyper proliferation of keratinocytes that may be complicated by arthritis
What are risk factors for Psoriasis
- Guttate - Streptococcal sore throat
- Palmoplantar - Smoking, middle-aged women, autoimmune thyroid disease
- Generalised pustular - Hypoparathyroidism
What are symptoms of Psoriasis
- Itching
- Pinpoint bleeding with removing scales
- Skin lesions may develop at sites of trauma
What are the signs of Psoriasis
Discoid/Nummular - Symmertrical, well-demarcated erythematous plaques with silvery scales over extensor surfaces
Flexural - Less scaly plaques in axilla, groins, perianal and genital skin
Guttate - Small drop-like lesions over trunk and limbs
Palmoplantar - Erythematous plaques with pustules on palms and soles
Generalised pustular - Pustules over limbs and torso - Hospitalisation (Sudden withdrawal of steroids)
Erythroderma - Generalised red, inflamed skin - Hospitalisation
Nails - POSH (Pitting, Onycholysis, Subungual Hyperkeratosis)
Arthritis
- Asymmetrical oligoarthritis
- Symmetrical polyarthritis
- DIP joint predominance
- Arthritis mutilans
- Psoriatic spondylitis
What are Cellulitis & Erysipelas
Cellulitis: Acute bacterial infection of the dermis and subcutaneous tissue
Erysipelas: Distinct form of superficial cellulitis which is sharply demarcated
What are causes of cellulitis
Streptococcus pyogenes
Staphylococcus aureus
Peri-orbital caused by Haemophilus influenzae
Risk factors:
- Skin break
- Poor hygiene
- Immunosuppression
- Wounds
- IV cannulation
What are signs and symptoms fo Cellulitis & Erysipelas
Hx of RFs
Peri-orbital - Painful swollen red skin around the eye
Orbital - Painful or limited eye movements, visual impairment
Lesion: Erythema, Oedema, Warm tender indistinct margins, Fever
Periorbital - Swollen eye lid, conjunctival infection
Orbital - Proptosis, impaired visual acuity and eye movement, Test RAPD, visual acuity and colour vision
How are Cellulitis & Erysipelas diagnosed
Bloods - WCC, Blood culture
Discharge - Sample and send for MC&S
Aspiration if pus suspected
CT/MRI - If orbital cellulitis is suspected (helps assess posterior spread of infection)
How are Cellulitis & Erysipelas treated
Mild cases:
- Draw around lesion
- Elevated leg
- Encourage oral fluids
- Paracetamol/ibuprofen
- Oral antibiotics: Local policy (Often flucloxacillin)
Admit if septic: Confusion, Tachycardia, Tachypnoea, Hypotension
Surgical: Orbital decompression may be needed in orbital cellulitis (Emergency)
Abscess: Aspirate, incision and drainage, excised completely
What are the 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
What is Varicella zoster
Primary infection is called varicella (Chickenpox). reactivation of the dormant virus (found in dorsal root ganglia) causes zoster (Shingles).
How is Varicella zoster transmitted
Aerosol inhalation or direct contact with vesicular secretions
ds-DNA
90% of adults VZV IgG positive (Immunity)
What are the signs and symptoms of chickenpox
- Prodromal malaise
- Mild fever
- Sudden appearance of intensely itchy spreading
- Vesicles weep and crust over
- New vesicles appear
- Contagious from 48hrs before the rash until after the vesicles have all crusted over (7-10days)
- Maculopapular rash
- Areas of weeping and crusting
- Skin excoriation (from scratching)
What are the signs and symptoms of shingles
- May occur after a period of stress
- Tingling/hyperaesthesia in dermatomal distribution
- Painful skin lesions
- Recovery: 10-14 days
- Vesicular maculopapular rash
- Skin excoriation
How is Varicella zoster diagnosed
Clinical diagnosis
- Vesicle fluid be sent for microscopy viral PCR
- Chicken pox in adult with previous history of varicella infection may require HIV testing
How is Varicella zoster treated
Chickenpox: Children - Treat symptoms (Antihistamine - Diphenhydramine), Adults - Consider acyclovir
Shingles: Aciclovir, Valaciclovir, Famciclovir
Prevention: Vaccine
What are complications Varicella zoster
Chickenpox:
- Secondary infection
- Scarring
- Pneumonia
- Encephalitis
- Congenital varicella syndrome
Shingles:
- Postherpetic neuralgia
- Zoster opthalmicus (Rash in the ophthalmic division of the trigeminal nerve)
- Ramsay-Hunt syndrome - 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
- Sacral zoster
- Motor zoster
