I have a teenage son, 19 years old, (height 183 cms, weight 90 kgs) who has been diagnosed with Henoch Schnolien Purpura a week ago. It started withpain abdomen on 21 oct. He was treated for ac gastritis for 3 days when he had a severe pain abdomen episode on 23 oct. was admitted and all tests carried out. platelet counts were normal. LFT- normal, TLC- mild leucocytosis (11,600) with 85 polymorphs. pancreatic tests normal (amylase 65). GI endoscopy done on 27 oct showed reflux esophgaitis. pain episodes continued. On 27oct he developed purpural rash over lower limbs and arms. with arthiritis of ankles on 30 oct. he was put on on steroids, prednisolone 40 +20 mg or last 3 days, but has had a fresh crop of purpura with pain abdomen.
other inv - IGA - mildly raised, ANA and ANCA - negative. ASO titre- mildly raised, USG abd - NAD, xray abdomen plain supine and erect- nad. repeat GI endoscopy on 01 nov - purpural rash on antrum of stomach and at duodenal junction. renal parameters normal. no hematuria detected. no melena or vomiting. no signs of intsusseption

addl medicines being give tab pantoprazole, inj tramadole (50 mg, SOS), Inj pcm 1gm, sos and mucaine gel

is the process of recurrent eruptions with pain abdomen a known phenomenon?
what should be the further course of treatment?
how long should the process continue?