What is Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis?
- Spectrum of the same pathology
- Blistering and epithelial sloughing
- Disproportional immune response causes epidermal necrosis
- SJS = LESS THAN 10% OF BODY AREA and mainly children
- TEN = more than 10% of the body area and all ages
- Certain HLA genetic types are at higher risk of SJS and TEN.
List drugs that can cause SJS and TEN.
- Anti-epileptics (phenytoin, carbamazepine, lamotrigine)
- Antibiotics (trimethroprime, ciprofloxacin
- Allopurinol
- NSAIDS
(Usually occurs 7-21 days after starting the medication in questions)
List infections that can cause SJS and TEN.
- Herpes Simplex
- Mycoplasma pneumonia
- Cytomegalovirus
- HIV
Describe the presentation of SJS and TEN.
Initially:
- Fever
- cough
- Sore throat
- Sore mouth
- itchy skin
Then:
- develop purple red rash (atypical lesions where lesions show two zone +/- indistinct borders)
- the rash breaks away and shed leaving raw tissue underneath (Nikosky’s Positive)
- Pain, erthyema, and blistering and shedding can also happen to the lips and mucous membranes
- Eyes can become ulcerated and inflamed
- Can also affect urinary tract, lungs and internal organs
A) List investigations for SJS and TEN
B) What scoring system is used to assess severity of infection in SJS and TEN?
A) FBC, CRP, BIOCHEMISTRY, COAGULATION STUDIES, MYCOPLASMA SEROLOGY, CHEST X-RAY, BIOPSY (NOT CRITICAL), SWAB FROM LESIONS FOR BACTERIOLOGY +/- VIRAL PCR
B)
- SCORTEN
Describe initial management of SJS and TEN.
1- Assess severity
2- Investigations and management
3- stop culprit drug
If BSA >10%, SCORTEN >1, or rapidly progressing then consider critical care.
Define erythroderma.
▪ Generalised erythema and edema affecting 90% or more of the skin surface
▪ Can be acute, sub-acute or chronic
- Fever, malaise, widespread skin redness, history of eczema or psoriasis
Causes:
▪ Dermatitis (especially atopic)
▪ Psoriasis
▪ Cutaneous adverse drug reaction (if drugs, then a maculopapular rash will be first) and pityriasis rubra pilaris
▪ Other rare causes and idiopathic in 30%
What is DRESS and AGEP?
DRESS = Drug Rash with Eosinophilia and Systemic Symptoms
- late onset (2-6 weeks)
- Fever and systemic symptoms
- Followed by rash, a classic maculopapular rash, can even present with erythoderma
- There is facial oedema and other organs are affected
- Drugs = anti-epileptics, sulphonamides, allopurinol, lamotrigine
AGEP = Acute Generalised Exanthemata’s Pustulosis
- acute and febrile
- less than 4 days onset
- prominent in flexors and there is tiny sterile pustules
- Neutrophilic eruption
- Drug culprits = B Lactams (pipercillian/tazobactam), and macrloides and CCB
What is acute Generalised pustular psoriasis?
- Wide spread sterile pustules on background of tender skin
- Triggered by withdrawal of corticosteroids (systemic or topical) and infection and pregnancy, or drugs like litium, aspirin, BB
- systemic symptoms (tachycarida, pyrexia, +/- hypotension)
What is Eczema herpeticum?
- Acute or acute-on-chronic eczema with super-imposed infection with herpes simplex virus or VZV
- presents with acute 24-27 development of painful monomophic vesciles and wrrosions in the head and neck area
- a lot of exudate and crust
Describe Basal cell carcinoma.
1- Most common
2- Metastasis is rare
3- slow growing
4- Typically a pearly nodule with a raised red edge, but can be scaly and it is often on the face
5- Well circumscribed
6- Ulcerated and pigmented
7- can bleed and can be painless (so may have crusting)
8- edges disappear into the skin, scar like
RF: Fair skin and sun exposure
Investigation: Large incisional biopsy to confirm histology (under local anaesthetic, to determined whether it has to be fully excised as some doesn’t need that)
Mx:
- Surgical excision (Mohs Microhgraphic surgery - you remove lesions and look under microscope to ensure it has been full removed)
- Can be treated topically (Imiquimod - applied daily, 5 days a week for 6 weeks - causes an aggressive local reaction)
- Do not use topical if on head or neck
- Cryotherapy for smaller superficial well defined lesions
- Vismodegib - systemic treatment used occasionally for inoperable BCC, a lot of SE’s including alopecia and taste disturbance
In which skin cancer should you not rely on a biopsy?
Pigmented lesions as a negative biopsy does not rule out melanoma
List risk factors for skin cancers
1- Age 2- Sun bed use 3- fair skin 4- Hx of sunburn 5- living overseas (e.g. australia) 6- FH 7- Phototherapy 8- occupations outdoors
Describe Squamous Cell Carcinoma.
a. Features:
i. Well-circumscribed
ii. Red elevations with scaly plaques (usually nodules, can be fleshy nodules or pigmented plaques)
iii. Related to UV exposure
iv. Less common than BCC’s
v. Small risk of metastases - mainly in the lymph nodes
vi. Not uncommon for SCC to appear in the same place as a previous one (Scalp = typical site)
vii. Some are derived from actinic Keratosis (Precancerous lesions - See below) Called Bowens disease
RF: SMOKING, SUN EXPOSURE, AND ACTINIC KERATOSIS
What is Bowens Disease?
SCC in situ (localised) - precancerous
Describe Actinic Keratosis.
1) Patho: keratoncytes damaged by UV light and produce too much keratin
2) AK: Dry, Rough scaly patches (like sand paper) from years of sun exposure ( can be red, pink, brown or skin-coloured< and may or may not stick out, and maybe itchy)
3) Rx: over 40, live in a sunny place, intense periods of sun exposure
4) Common places of appearance:
a) Face
b) Forearms
c) Hands
d) Scalp
e) Ears
f) Lower legs
5) Not serious but should be treated -> the lower the number of lesions = the lower the risk of SCC (So Tx is about reducing risk of SCC)
6) Treatment: Treat the lesions, and the field (the area around the lesions that has had the same UV light exposure so cells may be genetically damaged and risk of developing into something - the field is thread-like blood vessels (telangiectasis))
a) Topical Options:
i) Solaraze Gel (Diclofenac) - 1-2 a day, up to three months
ii) Efudix cream (5-fluorouracil) - once a day, for 4 weeks. But may notice a lot of inflammation so start every other day then increase
iii) Picato gel (ingenol mebutate) - could trigger skin cancer so not recommended
iv) Actikerall ointment (Fluroruracil+ salicyclic acid)
b) Cryotherapy - for single lesions
c) Curettage and cautery - if not responding to treatment, and you know there is sun damage, just in case
d) Emphasise use of high factor sunscreen and hat (between april and october)
Describe Seborrhoeic Keratosis.
Crusty
Often luck like they are ‘stuck on’
Like barnacles!
Are benign and can be left alone. Patient may decide they don’t like the appearance, or it may catch on clothing, or it may be itchy or irritating – all of which are reasonable indications for removal
Can shave off. Can use curettage (burn off)
Can cut off / frozen off
Not usually treated with topical agents
May be mistaken for melanoma as they are often pigmented
Describe melanomas.
a. Clinical Features
i. A: Asymmetrically shapes
ii. B: Borders = irregular
iii. C: Coloration varies
iv. D: Diameter > size of pencil eraser (>6mm)
v. E: Evolves rapidly + causes skin elevation
b. Types
i. Superficial spreading malignant - most common
ii. Lentigo malignant melanoma - head and neck of elderly patients
iii. Nodular/Amelanotic malignant melanoma
1) red nodules, they are most aggressive
2) Harder to diagnose
3) May look like pyogenic melanoma granuloma
4) (Beware of) red nodules in older patients
iv. Acral Lentiginous malignant melanoma
c. Management
i. Wide local excision
ii. Sentinel lymph node biopsy
1) Considered in patients with Breslow thickness of 1mm or more
2) Involved General Anaesthetic and overnight stay
3) Checks if melanoma has spread to the lymph nodes
iii. Drugs for advanced melanoma
1) Melanomas not very chemo sensitive
2) Targeted therapies showing promise (these are immuno therapies)
a) BRAF Mutation (patients are checked for this mutation before administring the therapy) drugs:
i) Vemurafenib - delays growth of advanced melanoma, oral
ii) Dabrafenib - slows/stops growth of BRAF Gene, oral, limited availability in the NHS
b) BRAF wild-type
i) Ipilimumab - monoclonal antibody, triggers immune system to attack cancer cells
d. Atyical Naevus Syndrome
i. Hereditary condition
ii. When person has over 50 moles, with 3 or more re atypical in their appearance (ie size (larger than 5mm) or shape, with flat and raised areas)
iii. Atypical moles on their own are usually benign with low risk of progression to cancer but in atypical naevus syndrome there is more than one and hence increased risk
iv. Only severe atypical individual moles/naevus have to be excised
v. Increased risk of melanoma and pancreatic cancer
A lady presents with a purplish non-blanching rash with painful papules on her legs and you suspect vasculitis.
A) List some of the common causes of vasculitis.
B) What are the antibodies that you look for in vasculitis
C) What are the general investigations.
A)
- Infections
- Connective tissue disease (SLE, systemic sclerosis)
- Malignancy (haematologic)
- Drugs (Antibiotics, antihypertensives)
- Idiopathic (HSP - inflammation disease of the small vessels)
B) ANA, ENA, ANCA
C) History and exam BP FBC U and E, LFT ANA, ENA, ANCA Urinalysis and urine albumin creatinine ratio Skin Biopsy +/- immunofluorescence
What are the three different different types of vasculitis?
- Small Vessel = palpable pupura and plaques
- Medium - assocaited with systemic vasculitis
Large = temporal arteritis
Describe Sarcoidosis/
- A granulomatous inflammatory condition (inflammatory nodules formed from macrophages)
- typically 20-40 yo woman
- Affects mainly lungs but the lesions can appears at any organ
- Associated with respiratory symptoms (dry cough and SOB)
- there is fibrosis in the lungs too
- Extra-respiratory = lymphadenopathy (hilar), and erythema nodosum
1- Bloods show:
- Raised serum ACE. This is often used as a screening test.
- Hypercalcaemia (raised calcium) is a key finding.
- Raised serum soluble interleukin-2 receptor
- Raised CRP
- Raised immunoglobulins
2- Imaging - CXR, CT/MRI
3- Histology - gold standard in making a diagnosis –> biopsy through a bronchoscopy –> non-ceasating /non-necrotising granulomas
Mx:
- First line is no treatment for those with mild or no symptoms
- then steroids + bisphosphnates to protect bone from long term steroid use
- Then methotrexate or azathioprine
What is erythema nodosum?
What causes it?
- Acute reactive inflammation of subcutis
- hot tender nodules
- fever, arthalgia, malaise
- self limiting
Causes:
- Infection
- Sacrdoidosis
- Malignancy
- Drugs (OCP, tETRACYLCINES)
- IBD
Describe the features of hypothyroidism.
Causes:
- Main common cause is hashimoto’s which is autoimmune (associated with Antithyroid Peroxidase Antibodies (AntiTPO)
- Iodine deficiency in developing countries
- Medications - lithium, amoidarone
- Secondary hypothyroidism with pituitary tumours
Sx:
- Weight gain
- Fatigue
- Constipation
- Hair loss/coarse heir
- dry skin
- irregular or heavy periods
- Fluid retention
Sigs: - Pretibial myxoedema - can lead to pruritis - dry skin 0 loss of 1/3 of eye brow
What is dermatitis Herpetiforms?
- Puritic vesicular eruption on elbows and buttocks
- associated with coeliac
- treat with gluten free and dapsone
