Practice this case based on how you are assessed in your OSCEs, and use the relevant sections for general revision. 🤓
Doctor Instruction:
You are currently a doctor working in an emergency department; your next patient is a 23-year-old female (Ms. Omega Three) presenting with a rash. Please take a history and perform an appropriate examination.
Patient History:
Your name is Omega Three – a 23-year-old female who is currently a student.
You noticed a few weeks ago you developed a rash around your arms like what you had as a teenager, but you do not remember what exactly is causing this rash. But this time, it is gradually getting worse, and currently, it is at its worst, so you have decided to see a doctor.
The rash is red, not itchy and is dry + scaly. Located at the back of the elbows and at the front of the knee. Since as a teenager, you noticed a bit of joint pain/ stiffness involving the wrists and fingers with some neck and lower back pain/stiffness that has been ongoing since you started the rash. Since then, the rashes have appeared intermittently.
The rashes are not particularly itchy – but you have been scratching them.
No rigors. No SOB/ cough. No N+V. No diarrhoea. No urinary symptoms. No recent infections you are aware of. No neck stiffness/ headache/ photophobia. No recent trauma. No recent change in medication.
Ideas, Concerns, Expectations:
You think this is just another rash you had in the past. You are not too sure what is causing this. A friend had a look at your rash thinking it was eczema. You are concerned that the rashes are getting worse and affecting your appearance – you find it embarrassing walking outside with short sleeves. You hope to get treatment as soon as possible – maybe some cream.
Past Medical History:
Nil
Drug History:
Nil
Allergic to penicillin (anaphylaxis)
Family History:
Father had a skin condition since a young age, but you do not know if this is eczema or psoriasis.
Social History:
You are currently a master's student studying mathematics – because of upcoming exam next week, you have been stressing and having poor sleep preparing for your exams.
You usually drink around 5-8 units spread over a week.
You do not smoke cigarettes, but you frequently use a vape.
Examination Findings:
Patches of erythematous, dry, flaky, scaly skin lesions that appear in raised and rough plaques over extensor surfaces of elbows, knees, and scalp
Thickened erythematous plaques with silver scales – the plaques are 1cm-10cm in diameter
Possibly small, scaly, erythematous raised papules across the trunk
Lesions are well-demarcated
No pustules
Nails may show nail pitting, thickening, discolouration, ridging and onycholysis (separation of the nail from the nail bed), subungual hyperkeratosis, and oil drop sign (yellow-red discolouration of the nail-bed)
Auspitz sign present – small points of bleeding when plaques are scraped off
Koebner phenomenon may be present (psoriatic lesions in the skin caused by trauma)
Residual pigmentation may be present
Fissuring within plaques may occur over joint lines/palms/ soles
Differentials:
Plaque/ guttate psoriasis
To rule out psoriatic arthritis
Any skin-associated condition with a good explanation, e.g. dermatitis, syphilis, pityriasis rosea, lichen planus, tinea corporis…etc.
Investigations: