Dermatology Flashcards
What’s that?
Pityriasis versicolour
aka Tinea Versicolour
keyword: hypopigmented patches
- it’s a superficial fungal infection
- caused by Malassezia furfur
May look similarly to vitiligo, but vitiligo would have more symmetrical pattern
Features of Pityriasis Versicolour
- most commonly affects the trunk
- patches may be hyperpigmented, pink or brown (since the name versicolour)
- maybe more noticeable following a suntan
- scale is common
- mild pruritis
Management of Pityriasis Versicolour
- topical antifungal → ketoconazole shampoo (for large areas)
If failure to respond to topical treatment → consider another diagnosis (e.g. send scrapings to confirm Dx)
- oral itraconazole
What’s that?
Acne rosacea
chronic skin condition, idiopathic
Features of acne rosacea
- typically affects nose, cheeks and forehead
- flushing is often the first symptom
- telangiectasia are common
- later develops into persistent erythema with papules and pustules
- rhinophyma
- ocular involvement: blepharitis
- sunlight may exacerbate symptoms
Management of acne rosacea
- topical metronidazole may be used for mild symptoms
- more severe disease is treated with systemic antibiotics e.g. Oxytetracycline
- recommend daily application of a high-factor sunscreen
- camouflage creams may help conceal redness
- laser therapy may be appropriate for patients with prominent telangiectasia
What’s that?
Pemphigus vulgaris
- an autoimmune disease
- antibodies directed against desmosomes
- present in younger people
- flaccid, easily ruptured vesicles, bullae and mucosal ulceration
Management: steroids, immunosupressants
Characteristics of the appearance of Pemphigus Vulgaris
- flaccid vessels, mucosal ulceration, bullae, vesicles that rupture easily
Potency of topical steroids
How much topical steroid to apply?
Finger tip rule
- 1 finger tip unit (FTU) = 0.5 g ⇒ sufficient to treat a skin area about twice that of the flat of an adult hand
What’s that?
Erythema multiforme
- a hypersensitivity reaction which is most commonly triggered by infections
- it may be divided into minor and major forms
Features of erythema multiforme
- target lesions
- initially seen on the back of the hands / feet before spreading to the torso
- upper limbs are more commonly affected than the lower limbs
- pruritus is occasionally seen and is usually mild
Causes of erythema multiforme
- viruses: herpes simplex virus (the most common cause)
- idiopathic
- bacteria: Mycoplasma, Streptococcus
- drugs: penicillin, sulphonamides, carbamazepine, allopurinol, NSAIDs, oral contraceptive pill, nevirapine
- connective tissue disease e.g. Systemic lupus erythematosus
- sarcoidosis
- malignancy
Management of erythema multiforme
- Mild disease (no systemic features) → treat at home with topical corticosteroid and oral antihistamine
- Severe disease with systemic features → systemic steroid (e.g. oral prednisolone) +/- admit to hospital
- if ocular involvement → refer to an ophthalmologist as emergency
Describe the rash
give a diagnosis
management
Maculopapular rash
Diagnosis: Measles
Features of Measles:
- prodrome: irritable, conjunctivitis, fever
- Koplik spots (before rash): white spots (‘grain of salt’) on buccal mucosa
- rash: starts behind ears then to whole body, discrete maculopapular rash becoming blotchy & confluent
Management
- mainly supportive
- admission may be considered in immunosuppressed or pregnant patients
- notifiable disease → inform public health
Management of contacts in Measles
- if a child not immunized against measles comes into contact with measles then MMR should be offered (vaccine-induced measles antibody develops more rapidly than that following natural infection)
- this should be given within 72 hours
Possible complications of Measles
- otitis media: the most common complication
- pneumonia: the most common cause of death
- encephalitis: typically occurs 1-2 weeks following the onset of the illness)
- subacute sclerosing panencephalitis: very rare, may present 5-10 years following the illness
- febrile convulsions
- keratoconjunctivitis, corneal ulceration
- diarrhoea
- increased incidence of appendicitis
- myocarditis
What’s that?
Hx: GP has given then antibiotics and they developed rash
Description: Maculopapular rash
Diagnosis: Infectious Mononucleosis (glandular fever)
What’s that?
Management
Management
mite Sarcoptes scabiei
- permethrin 5% is first-line
- malathion 0.5% is second-line
- give appropriate guidance on use (see below)
- pruritus persists for up to 4-6 weeks post eradication
Patient guidance on treatment:
- avoid close physical contact with others until treatment is complete
- all household and close physical contacts should be treated at the same time, even if asymptomatic
- launder, iron or tumble dry clothing, bedding, towels, etc., on the first day of treatment to kill off mites
Describe rash
Diagnosis
Description: well-defined annular, erythematous lesions with pustules and papules
Diagnosis: Tinea corporis (ringworm)
Management: topical/oral fluconazole
*oral only if topical therapy failed
Diagnosis
Management
Tinea Captis (scalp dermatophyte)
Management:
- oral antifungals: terbinafine
- topical ketoconazole shampoo should be given for the first two weeks to reduce transmission
