Table 1. Case reports of recurrent ITP following COVID-19 infection.

ITP - immune thrombocytopenia; PLT - platelet; IVIG - intravenous immunoglobulin; DEX - dexamethasone; PDN - prednisone; mPDN - methylprednisolone; HTN - hypertension; HLD - hyperlipidemia; CR - complete response

Complete response (CR) defined as platelet count returning to at least 100x10⁹/L

Response defined as platelet count returning to between 30-100x10⁹/L and at least doubling of the baseline platelet count

* ITP was diagnosed 27 days after the development of the first COVID-19 symptoms. The patient tested negative for COVID-19 using RT-PCR but clinical symptoms and chest CT were highly suggestive of COVID-19 infection

** Undetectable platelet count therefore recorded as <3x10⁹/L

Patient	Author	Gender and age (years)	Comorbid medical conditions	Initial ITP symptoms	Time from COVID-19 diagnosis to first ITP episode	Number of ITP relapses	Nadir platelet count  (x109/L)	Treatment	Total follow-up  (days)	Outcome
1	Our case	F, 30	None	Ecchymosis, fatigue	Eight weeks	Nine	3	IVIG 1g/kg/day for two days and PDN. Relapses: PDN or DEX, with or without IVIG. Romiplostim from day 119 to 262, Eltrombopag started on day 262, rituximab started on day 296	322	Multiple relapses alternating with response or CR
2	Mahevas et al. [17]	F, 62	Not reported	No bleeding seen	Nine days	One	9	PDN for five days	60	Response then relapse on day 58
3	Mahevas et al. [17]	M, 65	Not reported	No bleeding seen	One day	One	17	DEX for four days	60	CR then relapse on day 30
4	Mahevas et al. [17]	M, 53	Not reported	Purpura	27 days *	One	19	PDN for three weeks and IVIG for three days	50	CR then relapse on day 35
5	Bennett et al. [18]	F, 73	HTN, HLD	None	Concurrent	One	< 3 **	One unit of PLT, and IVIG 1 g/kg/day for two doses. Relapse: IVIG and DEX	33	CR then relapse on day 33
6	Kewan et al. [15]	M, 63	HTN	Petechiae, mucosal bleeding, epistaxis	30 days	One	2	DEX 40 mg for four days, IVIG for two days, and eltrombopag on days 5-28	61	CR then relapse (day not specified)
7	Serrano et al. [16]	F, 60	None	Ecchymosis, petechiae, retinal hemorrhages	Four weeks	Three	2	mPDN 1 mg/kg/day for two weeks. First relapse: four doses of rituximab 375 mg/m2/week IV, IVIG 1g/kg/day for two days, and DEX 40 mg/day for four days. Second relapse: DEX, IVIG, four doses rituximab, and eltrombopag. Third relapse: IVIG, eltrombopag, and DEX	100	Response, relapse on day 21, CR, relapse on day 35, CR, relapse on day 49, CR
8	Serrano et al. [16]	M, 74	Severe intellectual disability	Epistaxis and melena	Eight weeks	Two	6	PLT transfusion, IVIG 1 g/kg/day for two days. First relapse: IVIG, and DEX 40 mg/day for four days. Second relapse: IVIG, and eltrombopag 50 mg/day started	100	CR, relapse day 22, CR, relapse day 57, CR