LOs Flashcards
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