Picture Quiz
Case history
An eight year old girl was admitted with a
three day history of painful swollen joints. In
particular, her ankles were swollen and her
elbows were tender. That morning she had
developed a purpuric rash over her lower
limbs. She was afebrile. There was no previous history of a sore throat.
Questions
- What is the diagnosis?
- What is the differential diagnosis?
- What are the other clinical features of this condition?
Answers
- Henoch-Schönlein purpura.
- Purpura are small circumscribed lesions caused by bleeding into the skin. Causes may be divided into thrombocytopenia, vascular defects, coagulation abnormalities, and drugs. Low levels of platelets (thrombocytopenia) may be caused by idiopathic thrombocytopenic purpura (ITP), thrombotic thrombocytopenic purpura (TTP), or marrow disease such as leukaemia. Abnormalities of vessels include Henoch-Schönlein purpura, senile purpura, scurvy, uraemia, and gonococcal arthritis. Coagulation defects may be inherited or be due to disseminated intravascular coagulation (DIC). Iatrogenic causes include anticoagulation or steroids therapy.
- Gastrointestinal pain and bleeding (85% have symptoms, 5% have major bleeds or intussusception), fever (75%), arthralgia (75% of children, especially involving the knees and ankles), glomerulonephritis (40%), and rarely stroke, testicular haemorrhage, and testicular torsion.
Discussion
Henoch-Schönlein purpura is a condition
of unknown aetiology although it has
been postulated that it may be a post-streptococcal phenomenon, and a history of an upper respiratory tract infection is found in
two thirds of patients. Men are more commonly affected than women. The condition was first described in 1808 by Willan, but it
was Eduard Heinrich Henoch, studying
under Johannes Lucas Schönlein, Professor
of Medicine, in Berlin, who reported the
link between gastrointestinal symptoms
and a purpuric rash in 1874. The majority
of cases (75%) of the syndrome occur in
children aged less than 10 years. The condition is a small vessel vasculitis characterised by a non-thrombocytopenic purpuric rash, occurring particularly over the buttocks and lower limbs.
Urine should be tested regularly for
haematuria and proteinuria. Blood pressure,
urea, and creatinine should also be mea-
sured as markers of renal involvement. The
full blood count should demonstrate a
normal platelet count, and clotting studies
should be normal. A blood film should help
to exclude other important conditions such
as leukaemia or TTP. IgA levels will often be
raised and antistreptolysin titres (ASOT)
may be suggestive of recent streptococcal
infection. Treatment involves analgesia and
steroid therapy if there is bowel involvement. Steroids are not used for renal
involvement, and treatment for acute renal
failure may be required. The prognosis of
Henoch-Schönlein purpura is good, with
less than 15% of those who had initial renal
involvement going on to have further renal
complications.
Rajesh Thakkar, house officer
Duncan Rourke, senior house officer, The Whittington Hospital, London
studentBMJ 2000;08:259-302 August ISSN 0966-6494
