This case was provided to me by another physician and it has been anonymised for purposes of confidentiality.
A 50 year old female was seen in another hospital's out patient clinic because of a diffuse skin eruption.
She had been mildly unwell for 2 months with symptoms of an upper respiratory tract infection, the symptoms that included sore throat, mild fever, chills and nasal congestion. He was initially seen and given acetaminophen and multivitamins. Her throat examination at that time was red but with no exudate. No antibiotics were prescribed. No throat swabs were taken.
Her symptoms initially improved but there was a recrudescence of the same symptoms prompting a return to the hospital outpatient clinic. Again, medications for control of symptoms were prescribed and no antibiotics.
Two weeks before her current presentation, the URTI symptoms had completely resolved and she was feeling otherwise well.
However, after several days, her left knee began to hurt and she found it difficult to walk properly. There was no apparent swelling of the joint or preceding injury as mentioned by the patient.
A reddish-blue eruption began to emerge on her arms, legs and trunk. The eruption was composed of apparently very small areas of haemorrhage which were non-blanching and over approx 1-2m in diameter. The worse affected areas were her lower limbs. She also described other areas erupting after scratching her skin.
She denied visual disturbance, headaches, rectal bleeding or haematuria. Her other joints were non-painful.
She had described noticing blood in her mouth when cleaning her teeth and recent nose bleeds when blowing her nose hard several days before admission.
Previous medical history was nothing in particular apart from seasonal rhinitis.
She was taking no medications
She had no relevant family history and was a non-drinker and non-smoker.
On further questioning, she had no weight loss, a good appetite, no night sweats. No abdominal pains or other GI symptoms. In fact, she was otherwise feeling well.
Temp 36 C, Pulse 80 regular, BP 120/80, RR- 12, Sats 98% on RA. No Jaundice, Anaemia, Clubbing, Cyanosis, or Lymphadenopathy (JACCL)
She looked well but had a diffuse rash (as described above). Mouth- blue-black raised vesicle on the right lateral border of the tongue and on the buccal mucosa bilaterally. Elevation of the tongue revealed fresh blood in the lateral gutter at the junction of the floor of the mouth and the medial aspect of the gums.
CVS: JVP not raised. Heart sounds were normal. No evidence of DVT.
RESP: Percussion resonant, breath sounds vesicular.
ABDO: Soft, non-tender, no hepatosplenomegally. No ascites. Bowel sounds increased. Rectal examination not performed.
Left knee- mildly swollen. Not warm or tender. Bruising over infra-patella region. No patella tap. Crepitus on extending knee joint.
Oedema of both ankles.
Initial screening bloods were entirely normal except for a mild monocytosis, mildly raised CRP and BUN (20.1) but normal creatinine PLUS one other feature.
Question 1: Taking into account the history and examination what other feature from the CBC do you think is abnormal in this case?
Question 2: Why are her legs most affected and what is likely to be the likely diagnosis ?
Question 3: Why might the BUN be raised?
Question 4: Would you admit this patient into hospital even though she feels well or would you let her go home?
Question 5: What other tests would you like to perform?