Take an anti-inflammatory medication like ibuprofen as perscribed by your doctor.
Place an ice pack on your knee for 20 to 30 minutes every 3-4 hours for the first 2 or 3 days or until the pain goes...
There are no known treatments for the neurological defects of Lesch-Nyhan. The medication Allopurinol can lower blood uric acid levels. This medication does not correct many of the symptoms.