January practice questions

---

All answers with explanations can be found at the end of the page!

---

1. A 32-year-old lady is admitted to hospital with severe abdominal pain, vomiting, seizures, and general weakness. Examination is unremarkable but her urine is noted to be dark red. Which of the following is the most appropriate initial investigation in order to diagnosis the likely pathology? (1)

A. CT head 

B. Abdominal X-ray

C. Urinary porphobilinogen

D. 24-hour cortisol 

E. Urine ceruloplasmin

2. A 23-year-old woman presents to the emergency department with colicky abdominal pain and dark red urine for the past day. She reports stiffness preceding the onset of severe pain in her lower back and legs this morning. She has a known past medical history of porphyria and has recently started the combined oral contraceptive pill. 

Bloods and a urine dip are sent. Observations show a heart rate of 112 beats/min, temperature of 36.9ºC, respiratory rate of 20/min, and blood pressure of 110/82 mmHg.

Considering the most likely diagnosis, what is the first-line intravenous medical management? (2)

A. Glucose

B. Haem  

C. Co-amoxiclav 

D. Hypotonic fluids

E. Phenobarbital 

3. A 64-year-old man attends the GP complaining of a rash. He tells you that he first noticed fluid-filled blisters on the back of his hand which are fragile and rupture easily resulting in erosions.

On examination these erosions appear to be scarring. There is hypertrichosis of the malar region of the cheek.

Which of the following is the most likely diagnosis? (1)

A. Porphyria cutanea tarda

B. Pemphigus vulgaris 

C. Polymorphic light eruption 

D. Pellagra 

E. Cutaneous lupus erythematosus 

4. What are the histological findings of psoriasis? (3)

A. Inflammation of the dermal-epidermal junction

B. Keratin psuedocysts 

C. Acanthosis, parakeratosis and munro microabscesses 

D. Peripheral palisading of basal cells

E. Subepidermal blisters

5. What is this called - Psoriasis that develops in an area of trauma eg. scratch mark or scar.

A. Auspitz sign

B. Koebner phenomenon

C. Onycholysis

D. Pitting

E. Subungal Hyperkeratosis 

---

We hope you found these questions useful. For the answers, please refer below

---

Q1: C 

Explanation: Patient has features of an acute attack of intermittent porphyria. Urinary porphobilinogen (PBG) will be elevated in acute intermittent porphyria. 

Q2: B 

Explanation: This patient is presenting with symptoms consistent with acute intermittent porphyria and has a known past medical history of porphyria. Acute attacks most commonly occur in young women (it is uncommon in pre-pubescent or post-menopausal women). These can be precipitated by antibiotics, hormonal contraception, barbiturates, and seizure medications. The first line management for these patients is IV haem. 

Q3: A

Explanation: The rash and hypertrichosis are typical of Porphyria Cutanea Tarda. 

Q4: C

Explanation: Psoriasis is as a result of increased keratinocyte proliferation. It presents as salmon-coloured papules and plaques with silvery scaling, especially on extensor surfaces and scalp. On histology, there is epidermal hyperplasia (acanthosis), hyperkeratosis with retention of nuclei in stratum corneum (parakeratosis) and groups of neutrophils in the stratum corneum (Munro microabscesses). 

Q5: B

Explanation: Koebner phenomenon is the correct answer. 

• Auspitz sign: bleeding points where the surface scale is removed

• Onycholysis: separation of nail plate from nailbed

• Nailbed pitting: superficial depressions in the nailbed

• Subungual hyperkeratosis: thickening of the nailbed

References: 

1. Dermatology questions [Internet]. Quesmed. 2024. Available from Quesmed.com

2. Dermatology questions [Internet]. Passmed. 2024. Available from Passmedicine.com 

3. Dermatology Quiz [Internet]. Geeky medics. 2024. Available from Geekymedics.com