I was unable to find an established protocol for steroid taper in patients with eosinophilic myocarditis. As in your case, prompt response to glucocorticoids is widely reported. There is a wide range of starting doses, from 30mg to as high as 100mg, with each reporting successful therapeutic response. So, your initial dose of 60mg is in the middle of the range and was therapeutically successful. As you know, in addition to peripheral total eosinophil count, it is important to monitor cardiac status. I found two references that detailed the steroid taper. Both of which tapered to 10mg daily, followed by a slower, clinically based taper.
Kaneda, et al. (1) reported a prompt response to relatively low dose prednisone (30mg/day), followed by a taper of 5mg per week to 10mg per day. 10mg per day was then tapered more slowly based on clinical evidence.
Eppenberger, et al. (2) Reported a more aggressive management of 100mg prednisone, with a more aggressive taper to 10mg per day over 4 weeks. The prednisone was then tapered more gradually at 2.5mg intervals.
(1) Kaneda T, Iwai S, Suematsu T, et al. Acute necrotizing eosinophilic myocarditis complicated by complete atrioventricular block promptly responding to glucocorticoid therapy. Journal of Cardiac Cases. 2017;16(1):5-6
(2) Eppenberger, Manuela et al. “Acute eosinophilic myocarditis with dramatic response to steroid therapy: the central role of echocardiography in diagnosis and follow-up.” Texas Heart Institute Journal vol. 40,3 (2013): 326-30.
I hope this is helpful in the management of your patient.
Jeffrey Demain, MD, FAAAAI