Pathology Part 3 Flashcards
Erythroderma
Refers to the clinical state of inflammation or redness of all (or nearly all) of the skin - medical emergency
Cuases of Erythroderma
o Atopic eczema
o Psoriasis
o Drugs
o Idiopathic
Drug causes of Erythroderma
- Sulphonamides
- Gold
- Sulfonylurea
- Penicillin
- Allopurinol
Erythema nodosum
Inflammation of subcutaneous fat
Features of Erythema nodosum
> Tender, erythematous, nodular lesions
Usually occurs over shins, may also occur elsewhere
Usually resolves within 6 weeks
Lesions heal without scarring
Infection causes of Erythema nodosum
- streptococci
- tuberculosis
- brucellosis
Systemic disease causes of Erythema nodosum
- sarcoidosis
- inflammatory bowel disease
- Behcet’s
Drug causes of Erythema nodosum
penicillins
sulphonamides
combined oral contraceptive pill
Other causes of Erythema nodosum
Pregnancy and malignancy
Treatment for Erythema nodosum
- Symptomatic – NSAIDs
2. Light compression bandaging and bed rest
Erythema multiforme
A hypersensitivity reaction which is most commonly triggered by infections. It may be divided into minor and major forms.
Two types of Erythema multiforme
Erythema multiforme minor
Erythema multiforme major
Features of Erythema multiforme
> Target lesions > First back of the hands/feet before spread to torso > Pruritus > Resolves in 2-4 weeks > No mucosal involvement
Causes of Erythema multiforme
- Viruses: herpes simplex virus
- Idiopathic
- Bacteria: Mycoplasma, Streptococcus
- Drugs
- Erythematosus
- Sarcoidosis
- Malignancy
Drugs that cause Erythema multiforme
Penicillin sulphonamides carbamazepine allopurinol NSAIDs oral contraceptive pill nevirapine
Erythema multiforme major
The more severe form, erythema multiforme major is associated with mucosal involvement.
What do the target lesions in Erythema multiforme look like?
Erythematous, polycyclic, annular concentric rings
Pyoderma gangrenosum
A rare, non-infectious, inflammatory (neutrophilic dermatosis) disorder. It is an uncommon cause of very painful skin ulceration. It may affect any part of the skin, but the lower legs are the most common site.
Causes of Pyoderma gangrenosum
> idiopathic in 50% > inflammatory bowel disease in 10-15% > rheumatoid arthritis > SLE > lymphoma > Liver disease
Pyoderma gangrenosum features
Erythematous nodules or pustules that frequently ulcerate
> Bluish-black (gangrenous) edge
> May be associated pyrexia and malaise
Treatment for Pyoderma gangrenosum
- Very potent topical steroids
- Immunosuppressants used in resistant cases
- Underlying cause should be treated
Acanthosis nigricans
Describes symmetrical, brown, velvety plaques that are often found on the neck, axilla and groin.
Causes of Acanthosis nigricans
Type 2 diabetes mellitus Gastrointestinal cancer Obesity Polycystic ovarian syndrome Acromegaly Cushing's disease Hypothyroidism Familial Prader-Willi syndrome
Drugs that cause Acanthosis nigricans
- Combined oral contraceptive pill
2. Nicotinic acid
Scleroderma
Thickening or hardening of the skin owing to abnormal dermal collagen
Pathophysiology of Acanthosis nigricans
Insulin resistance → hyperinsulinemia → stimulation of keratinocytes and dermal fibroblast proliferation via interaction with insulin-like growth factor receptor-1 (IGFR1)
Management of acanthosis nigricans
Oral or topical retinoids
Dermatomyositis
A variant of polymyositis - an inflammatory disorder causing symmetrical, proximal muscle weakness and characteristic skin lesions
Features of dermatomyositis
- photosensitive
- macular rash over back and shoulder
- heliotrope rash in the periorbital region
- Gottron’s papules
- nail fold capillary dilatation
Investigations in dermatomyositis
ANA positive
anti-Jo-1
anti-SRP
anti-Mi-2 antibodies
Treatment for dermatomyositis
o Hydroxychloroquine
o Immunosuppressants
Sarcoidosis
A multisystem disorder of unknown aetiology characterised by non-caseating granulomas. It is more common in young adults and in people of African descent
Sarcoidosis features
> Erythema nodosum, > bilateral hilar lymphadenopathy, > swinging fever, > polyarthralgia > dyspnoea, > non-productive cough, > malaise, > weight loss > Hypercalcaemia
Lofgren’s syndrome
Is an acute form of sarcoidosis characterised by bilateral hilar lymphadenopathy (BHL), erythema nodosum, fever and polyarthralgia. It usually carries an excellent prognosis
Mikulicz syndrome
There is enlargement of the parotid and lacrimal glands due to sarcoidosis, tuberculosis or lymphoma
Heerfordt’s syndrome
There is parotid enlargement, fever and uveitis secondary to sarcoidosis
What are the two type of Neurofibromatosis?
NF1
NF2
Neurofibromatosis
A group of autosomal dominant genetic disorders that cause tumors to form on nerve tissue. These tumors can develop anywhere in the nervous system.
Features of NF1
- Café-au-lait spots (>= 6, 15 mm in diameter)
- Axillary/groin freckles
- Peripheral neurofibromas
- Iris hamatomas (Lisch nodules) in > 90%
- Scoliosis
- Pheochromocytomas
Café-au-lait spot
Feature of NF1 and Tuberous sclerosis
Tuberous sclerosis (TS)
A genetic condition of autosomal dominant inheritance.
Causes benign growths in many parts of the body
Features of cutaneous Tuberous sclerosis (TS)
- Depigmented ‘ash-leaf’ spots - fluoresce under UV
- Shagreen patches
- adenoma sebaceum (angiofibromas)
- Subungual fibromata
- Café-au-lait spots* may be seen
Shagreen patches
An irregularly shaped, irregularly thickened, slightly elevated soft skin-colored patch, usually on the lower back, made up of excess fibrous tissue.
Subungual fibromata
A painless, slow-growing tumor seen in the nail apparatus
Adenoma sebaceum (angiofibromas)
Refers to the reddish-brown papular rash found characteristically in a “butterfly” distribution over the face.
Bopsy and immunoflourescene is gold standard to identify and distinguish between pemphigoid and pemphigus. What are the differences seen?
Pemphigoid: linear IgG on IF
Pemphigus: scattered IgG on IF
Pemphigus vulgaris
Is an autoimmune disease caused by antibodies directed against desmoglein 3, a cadherin-type epithelial cell adhesion molecule. It is more common in the Ashkenazi Jewish population.
Features of Pemphigus vulgaris
> Mucosal ulceration
Flaccid, easily ruptured vesicles and bullae.
Nikolsky’s positive
Acantholysis on biopsy
Nikolsky’s sign
The sign is present when slight rubbing of the skin results in exfoliation of the outermost layer.
Acantholysis
Means loss of coherence between epidermal cells due to the breakdown of intercellular bridges.
Management of Pemphigus vulgaris
- High dose oral prednisolone
2. Immunosuppressants
Bullous pemphigoid
An autoimmune condition causing sub-epidermal (basement membrane) blistering of the skin. This is secondary to the development of antibodies against hemidesmosomal proteins BP180 and BP230.
Features of Bullous pemphigoid
- Itchy, tense blisters typically around flexures
- the blisters usually heal without scarring
- there is usually no mucosal involvement (i.e. the mouth is spared)*
- Nikolsky negative
Difference in location of blisters in Pemphigus and Pemphigoid
Pemphigus - intraepidermal - Nikolsky positive
Pemphigoid - subepidermal (Dermo-epidermal junction)
Dermatitis herpetiformis
An autoimmune blistering skin disorder associated with coeliac disease. It is caused by deposition of IgA in the dermis.
Features of Dermatitis herpetiformis
o Commoner in males
o Small intensely itchy blisters of the skin
o Appear on the elbows, extensor forearms, scalp and buttocks
Management of Dermatitis herpetiformis
Gluten-free diet
Dapsone
Dapsone
A sulphonamide antibiotic.
It acts as an anti-inflammatory drug and has been used successfully as a treatment for several skin conditions such as dermatitis herpetiformis & pyoderma gangrenosum,
Biopsy features in Dermatitis herpetiformis
Show IgA in the dermal papillae and patchy granular IgA along the basement membrane
The jejunal mucosa shows a partial villous atrophy
Filaggrin
A protein that increases risk of eczema, hay fever and asthma
Porphyria cutanea tarda (PCT) type 1
Blisters, fragility, hyperpigmentation, hypertrichosis
Manage the skin condition and underlying cause
Capsaicin
Antipruritic - active component of chill peppers
Gorlin’s syndrome
o Autosomal dominant familial cancer syndrome
o Multiple BCC
o Early onset
Spongiosis
Oedema between keratinocytes
Epidermolysis bullosa
Is where the skin blisters on minimal trauma (inherited)
Example of mild steroid
1% hydrocortisone
Example of moderate steroid
Eumovate
Example of potent steroid
Betnovate
Example of very potent steroid
Dermovate
Immune thrombocytopenic purpura
Immune disorder characterised by platelet-bound antibody, often with a previous history of infection.
Blood tests show a very low platelet count
Erythema migrans
o Bulls eye appearance
o Caused by a tick bite
o Early sign of lyme disease
o Red macule surrounded by another red circle, with non-affected skin in between
Herpangina
Blistering rash of the back of the mouth
Caused by enterovirus (not herpes virus)
> Coxsackie virus
> Echovirus
Angioma vessels
Benign localised overgrowth of blood vessels
Target lesion
Erythema multiforme
Large tense bullae that are itchy and cannot be burst
Bullous pemphigoid
Flaccid blisters that can be burst easily to form erythematous erosions
Pemphigus vulgaris
Heliotrope rash and scaly knuckles
Dermatomyositis
Cauliflower appearance
Plantar warts
Silver scales, extensor surface
Plaque psoriosis
Honey-colored crust
Impetigo
Stuck on appearance
Basal cell papilloma
Androgenic alopecia
o Male pattern baldness
o Positive family history
o Frontal receding with thinning of the crown
o May occur in females following menopause
Alopecia areata
o Immune mediated hair loss
o Patches of baldness
o Broken exclamation mark hairs
Hirsutism
Male pattern hair growth seen in females
Hypertrichosis
State of excessive hair growth at any site and occurs in both sexes
Neuropathic ulcers
Tend to be seen over pressure areas of the feet, such as the metatarsal heads
Most commonly seen in diabetics due to peripheral neuropathy - Painless
Neuropathic ulcers management
- Keeping the ulcer clean
- Remove pressure or trauma from the affected area
- See a podiatrist for correctly fitting shoes
Arterial ulcers
o Present as punched-out, painful ulcers o Higher up the leg o “Sharp cliff-like edge” o The leg is cold and pale o Absent peripheral pulses o Loss of hair may be present
Arterial ulcers management
- Compression bandaging must NOT be used
- Keep the ulcer clean and covered
- Adequate analgesia and vascular reconstruction
Venous ulcers management
- High compression bandaging
- Leg elevation
- Doppler studies should always be done before bandaging to exclude arterial disease
- Analgesia
- Wet/moist ulcer dressing
Why should doppler US studies be done before compression bandaging in venous ulcers?
Doppler studies should always be done before bandaging to exclude arterial disease
Venous ulcers
Result of sustained venous hypertension in the superficial veins due to incompetent valves or previous DVT
o Common later in life and cause significant
o “Shallow like a beach”
o Chronic and recurrent
o Most commonly found on the lower leg
Melanocytic naevi (moles)
o Benign overgrowth of melanocytes that are common in white-skinned people
o Appear in childhood and increase in number and size as you get older
o Start flat and as they proliferate they become elevated
o Even pigmentation and regular border
Blue naevus
Acquired symptomatic blue-looking mole
Basal cell papilloma (seborrhoeic wart)
o Common benign overgrowth of the basal cell layer of the epidermis
o Surface is irregular and appear ‘stuck on to the skin’
o Can be treated with cryotherapy
Another name for Basal cell papilloma
Seborrhoeic wart
Dermatofibromata
o Firm, elevated pigmented nodules that may feel like a button on the skin
o Peripheral ring of pigmentation is sometimes seen
o Often on the leg, commoner in females
A dermatofibroma is the name we give to a common and harmless knot of fibrous tissue which occurs in the skin. Dermatofibromas are firm bumps which feel like small rubbery buttons lying just under the surface of the skin.
Solar keratosis (actinic keratosis)
> Significant sun exposure
Exposed skin as erythematous silvery-scaly papules or patches
Background skin is inelastic, wrinkled with flat brown macules (solar lentigos) reflecting diffuse solar damage
What is the risk of Solar keratosis (actinic keratosis)
A small proportion can transform into SCC after many years
Another name for Solar keratosis
Actinic keratosis
Treatment for Solar keratosis
- Crytotherapy
2. Topical 5-flourouracil cream
Bowen’s disease
Form of intrapeidermal carcinoma-in-situ which can become invasive - Due to long-term sun exposure
Presents on exposed skin, most commonly on women’s legs, as an isolated scaly red patch or plaque looking rather like psoriasis
Bowen’s disease management
- Crytotherapy
2. Topical 5-flourouracil cream
Giant congenital melanocytic naevi
o Very large moles present at birth
o Increased risk of developing malignant melanoma
Lentigo maligna
o Slow-growing macular area of pigmentation seen in elderly people, commonly on the face
o Border and pigmentation are often irregular
o Increased risk of developing invasive malignant melanoma
Risk of Lentigo maligna
Increased risk of developing invasive malignant melanoma
Most common malignant skin tumour
Basal cell carcinoma (rodent ulcer)
Basal cell carcinoma features
Can present as a slow-growing papule or nodule that may go on to ulcerate
Telangiectasia over the tumour or a skin-coloured jelly-like ‘pearly edge’ may be seen
Basal cell carcinoma
Most common malignant skin tumour
Common later in life on exposed sites (although rare on the ear)
Basal cell carcinoma management
Surgical excision
What area is rare for BCC to develop?
The ear
Squamous cell carcinoma
o More aggressive than BCC and can metastasize
o Can arise in pre-existing bowen’s disease
o Ill-defined nodules that may ulcerate
o Grow rapidly
o Examination of regional lymph nodes is essential
o Most common on sun-exposed sites, particularly lower lip and ear
Risk factors for SCC
- excessive exposure to sunlight
- actinic keratoses and Bowen’s disease
- immunosuppression e.g. renal transplant, HIV
- smoking
- long-standing leg ulcers (Marjolin’s ulcer)
- genetic conditions e.g. xeroderma pigmentosum,
- oculocutaneous albinism
Common sites for SCC
Lower lip & ear
Malignant melanoma
o Most serious form of skin cancer
o History of childhood sun exposure and intermittent intense sun exposure appears to be necessary
Risk factors for Malignant melanoma
> Pale skin > Multiple melanocytic naevi (>5) > Immunosuppression > Family history > Lentigo maligna
Most common Malignant melanoma
Superficial spreading
The 4 types of malignant melanoma
Superficial spreading
Nodular
Lentigo maliga
Acral lentiginous
Second most common Malignant melanoma
Nodular
Most aggressive Malignant melanoma
Nodular
Superficial spreading malignant melano sites of invasion
Arms, legs, back and chest, young people
Nodular malignant melano sites of invasion
Sun exposed skin, middle-aged people
Lentigo maliga (malignant melanoma) sites of invasion
Chronically sun-exposed skin, older people
Acral lentiginous malignant melano sites of invasion
Nails, palms or soles, African Americans or Asians
