Dermatology: The basics Flashcards
Patient presents with areas of raised pink skin. They say its bothering them how itchy it is. It came on after falling into a ditch while out hiking. There is no evidence of other skin changes or swelling.
1) What is the likely diagnosis?
2) What tests would you like to do?
3) How do you treat it?
1) Urticaria: Itchy ‘wheals’ consisting of pink raised skin. Due to superficial swelling caused by mast cells.
2) None usually required (see NICE for considered)
3) Identify and avoid triggers
Cetirizine/fexofenadine/loratadine (NSAHs) for up to 6 weeks
+ Oral corticosteroid (prednisilone) for 7 days if severe
When should referral to a dermatologist/immunologist be made for urticaria?
- Painful and persistent (think vasculitic urticaria)
- Poor control on anti-histamine treatment
- Acute severe due to food or latex
- Chronic inducible caused by difficult triggers such as Solar or cold
Patient presents with swelling around their lips and tongue. They state that the affecteed areas feel more painful than itchy. They state the swelling came on gradually following being stung by a bee during a walk. They deny any breathing difficulties and dont have any skin changes
1) What is the likely diagnosis?
2) What investigations should be performed?
3) What is the management?
4) How would the management differ if the history had sudden onset and breathing difficulties
1) Angioedema without anaphylaxis: Swelling of the deeper mucosa due to an allergic response or drug reaction.
2) None, clinical diagnosis
3) Slow IV/IM chlorphenamine and hydrocortisone if rapidly developing
Identify and avoid underlying cause
Avoid ACEis and AR2Bis
+ Oral NSAHs
4) ABCDE
Give IM adrenaline
What are the age-related dosages of IM adrenaline 1:1000?
<6 months: 100-150ug (0.1-0.15ml)
6m-6yrs: 150ug (0.15ml)
6-12 yrs: 300ug (0.3ml)
>12yrs: 500ug (0.5ml)
Regarding follow up for angioedema, how long should a non-sedating antihistamine be given for in…
- Acute allergic angioedema
- Likely persistence/recurrence
- Long history of urticaria/angioedema
- Daily for up to 6 weeks
- Daily for up to 3-6 months
- Daily for 6-12 months
What circumstances would allow an anaphylaxis patient be discharged…
- After 2 hours
- After 6 hours
- After 12 hours
- Good response to single dose and trained to use autoinjector
- 2 doses needed OR previous biphasic reaction
- >2 doses needed, severe asthma, slow reaction, difficulty accessing care if it recurs
Regarding the lesion
1) What is the lesion
2) What infecti
3) How do you differentiate from pyoderma
1) Erythema nodosum: Discrete tender nodules that last 1-2 weeks and leave bruise like changes
2) Loads of stuff
Infections: GAS, TB, chlamydia, leprosy
Sytemic: Sarcoidosis, malignancy, IBD
Drugs: Penicillin, sulphonamides, COC pill
Pregnancy
3) Pyoderma gangrenosum
red bumps/blister that then breaks down into ULCER
6 year-old patient presents with a rash. It is a red, itchy rash that extends across the back and described as having ‘rings inside rings’. Their parent states that they have had a temperature and a sore mouth.
1) What is the condition?
2) What causes it?
3) How can it be differentiated from SJS and TEN?
4) How are the above treated?
Erythema multiforme: ‘Target lesions’ that spreads form hands/feet to torso. Mild pruritis may also occur.
Typically caused by HSV
Can be caused by bacteria, drugs or systemic disease
Limited to one mucosal surface whereas SJS is two or more (eg mouth)
TEN has systemic toxicity
Early call for help then supportive to manage haem stability
Patient presents with full body rash with the skin appearing inflammed, oedematous and scaly. They also state they feel poorly. They have a history of eczema and lymphoma. They have recently been admitted to hospital for a severe gastroenteritis, receiving vacomycin
1) What is it
2) What causes it
3) How to manage it?
1) Erythroderma: Where >95% of body is covered in rash of any kind.
2) Atopic skin, lymphomas, drugs (inc gold), idiopathic
3) Treat underyling cause
Wet wraps and emollients for skin moisture
Topical steroids may help to releive inflammation
Patient presents with a rash. It consists of extensive crusted papules, blisters and erosions; it covers their chest and face. The patient also feels poorly in themselves. They have a PMHx of atopic eczema.
1) What is the likely diagnosis
2) What causes it?
3) What is the treatement?
1) Eczema herpeticum: Widespread eruption of crusted papules and blisters
2) Due to HSV 1/2
3) Admission for IV aciclovir
Patient presents with acutely unwell. They have felt unwell 2 days after being treated for a severe burn on their legs. They have a history of DM managed with metformin and dapagliflozin.
1) What is it?
2) What causes it?
3) How do you manage it?
Necrotising fascitis: Acute onset of pain, swelling and redness at the site, looks like cellulitis with out of keeping pain.
2) Mix of anaerobes and aerobes (esp diabetics) or S.pyogenes
3) Urgent debridement
IV antibiotics
Patient presents with a red, hot, swollen and tender skin that has spread rapidly up their leg. They also say they are feeling hot. They state that they did cut their legs when doing DIY yesterday.
1) What is the diagnosis?
2) How is this differentiated from a similar condition?
3) How is this managed?
1) Cellulitis: Sudden onset of local inflammation following deep tissue infection, usually by S.aureus. Systemic unwellness and lymphangitis can also happen.
2) Erisepelas presents similarly but has a well-defined, red raised border
3) Depends on Eron Class
Systemically well and no co-morbidities (I)/unwell or co-mobitidies (II): Oral antibiotics
Significant systemic upset or unstable co-morbidities or vascular compromise (III): Admit for IV
Sepsis syndrome/severe infection (eg necrotising fasciitis) (IV): Admit for IV
What are the typical antibiotic options for cellulitis?
1st line: Flucloxicillin
clarithromycin or doxycyline if above not suitable
Erythromycin (pregnancy)
Infant presents with a widespread rash. The patients skin is red in the axillae, neck and face. You also note crusting around the patient’s mouth. In the armpit you see a large, flimsy blister. The patient is in significant pain with the blister.
1) What is it?
2) How is it managed?
Staphyloccocal scalded skin syndrome: ‘scalded’ apperance of the skin with subsequent development of flaccid bullae that are very painful. Perioral crusting can also be seen.
Treat with Co-amox/fusidic acid/erythromycin or cephalosporin
Appropriate analgesia
Patient presents with an itchy scale in their left groin region. They have a background of rheumatoid arthritis. They had been backpacking through rural brazil.
1) What is the diagnosis?
2) What investigations?
3) How do you manage?
4) What treatement should be avoided?
1) tinea infection (cruris): Fungal infection of the skin, typically presents as unilateral itchy skin +/- scales. Seen in immunosuppressed and moist environments.
2) Sample surfaces: skin swabs +/- nail clippings, hair samples
3) Deal with underlying cause (ie good hygiene, Immuno problems)
Oral antifungal (azoles) if severe
4) AVOID TOPICAL STEROIDS: can cause tinea incognito
Patient presents worried about their skin. They had been out tanning the day previous and noted the areas near their armpit did not tan.On examination, you see mutliple round macules
1) What is the diagnosis?
2) What investigations do you want to do?
3) What is the management?
4) How can recurrence be prevented?
- Pityriasis versicolour: Commensal yeast infection causing altered pigmentation of the skin (red/brown/pink/white)
- Diagnosis is clinical
- Topical antifungal if small
Ketoconazole 2% shampoo if large
Oral if resistant
- Can prevent with once fortnightly/monthly shampoo application
Patient presents with a lump on their face. It sits just beside their nose. The lesion has shiny rolled edges and surface telangectasia. They are worried as their sister was diagnosed with melanoma last year, having to cancel their biannual visit to Dubai.
1) What is the diagnosis?
2) What investigations should you do?
3) What is the management plan?
1) Basal cell carcinoma: lesion of varying morphology but most commonly nodular, shiny rolled edges and telangectasia present. Can have ulcerated centre (Rodent Ulcer)
2) Histological examination following excision
3) Surgical excsion
Can use Moh’s (gradual excision) if hihg risk or recurrent
Radiotherapy if not appropriate
Patient presents to GP with a lump beside their nose. It is scaly, poorly defined and appears ulcerated. The patient has a background of Crohn’s disease and uses sunbeds regularly.
1) Whats the diagnosis?
2) What investigations
3) What management is needed?
- Squamous cell carcinoma: Keratotic, ulcerated and poorly defined lesion affecting those with UV exposure, pre-malignant skin and immunocompromised.
- Clinical diagnosis
- Surgery/Mohs
Radiotherapy if large, unresectable
How can thickness of skin SCC influence outcomes?
Breslow Thickness
<0.76mm: Low risk
0.76-1.5mm: Medium
>1.5mm: High risk
10 year old presents with itchy, scaly spots on top of reddened skin on the front parts of the knees and back parts of elbows. They have a background of asthma. Their mum states that they have been stressed as there is a high school entrance exam coming up.
1) Diagnosis?
2) Investigations?
3) Treatment?
- Atopic eczema: itchy, red,scaly skin. More common on face and extensors in infants, flexors in children.
- Clinical
- Avoid exacerbating agents
Topical steroids or -limus (immunomodulators) can be used
Phototherapy for severe non-responsive agents
What infections are eczema patients more likely to get?
Molluscum contagiosum (pearly papules with central umbilication)
Viral warts
Eczema herpeticum
14 year old presents with red spots across the face and back, some of which are fluid filled. They are worried as they try to take care of their skin but the spots won’t disappear.
- Diagnosis?
- Investigations?
- Acne vulgaris: areas of dilated follicles which are white when open, black when closed. When inflamed red, bumpy skin happens and can lead to nodules or cysts. Scarring can then results. these can all coexist in the same patient.
- Clinical
What is the treatment for mild-moderate acne?
First line combo of:
Adapelene (retinoid) + Benzoyl Peroxide
OR
Benzoyl peroxide + clindamycin
OR
Clindamycin + tretinoin
What is the initial treatment for severe acne?
12 weeks of one of the following
topical tretinoin + topical clindamycin.
adapalene + benzoyl peroxide + oral lymecycline 408 mg OR oral doxycycline 100 mg once daily.
Azelaic acid (15% or 20%) + lymecycline 408 mg OR oral doxycycline 100 mg once daily.
What acne antibiotics must be avoided in pregnancy?
What can be used as an alternative?
Tetracyclines eg doxycycline
Erythromycin is an alternative
Apart from topical agents, what other options can be used in acne?
Combined Oral Contraceptive pill (DIANETTE SHOULD BE USED AFTER TRYING ANOTHER ONE)
Oral isotretinoin: Need to be supervised
Patient presents with a rash. It is red, raised and scaly, extending over the back of their left elbow. The patient says it has been itchy the past week. On examination you notice their fingernails are raised from their beds.
1) What is the diagnosis?
2) What investigations are you going to do?
3) How do you manage the condition?
- Psoriasis: Red, raised and scaly skin that can be itchy. Can be large plaques, raindrop shaped (guttate), facial, scalp or erythrodermic (>90% coverage) or pustular.
- Clinical
Management: Scale up if no improvements after 8 weeks
- Strong corticosteroid + vitamin D, one morning and one evening
- Vit D twice daily
- Steroid twice daily for 4 weeks OR coal tar 1-2 daily
+ dithranol
What are the secondary care options for psoriasis?
Phototherapy: Narrowband UVB 3x week
Systemic therapy: Oral methotrexate first line
What should be considered with topical steroid use in psoriasis?
Scalp, face and flexures are prone to atrophy so no more than 1-2 weeks/month
>10% coverage can cause systemic effects
Take 4 weeks between different steroids
What are the pros and cons of vitamin D analogues in psoriasis?
Pros: long term use, dont smell
Cons: Dont reduce redness, avoid in pregnancy
When should a psoriasis case be referred?
Severe/non responsive disease
disease affecting >10% body
Nail disease severe
