Thank you for your inquiry.
As you know, there is no definitive answer to your question, and the decision as to whether or not to challenge this boy with risperidone is really one based on a risk/benefit analysis. I think that the differential lies between idiopathic angioedema (which would be somewhat unusual in a boy this age) and risperidone-induced angioedema.
I obtained the article which you mentioned, and there are actually two other cases of angioedema associated with the administration of risperidone (references copied below). Thus, clearly risperidone-induced angioedema is rare, but nonetheless based on these reports can occur.
If risperidone, however, is considered essential, then I believe you would be forced to try readministration. I think the dose you have selected is a good starting point. However, based on the fact that in one of the cases cited below, the patient was able to tolerate a lower dose of risperidone but had a recurrence of angioedema when the dose was increased, there is no guarantee that your patient (even though he could take a lower dose) could tolerate the full therapeutic dose. Unfortunately, the only way to tell is to challenge.
If there is no alternative medication for this boy, I would suggest a challenge with the 0.125 mg dose, and increase the amount as slowly as the psychiatrist feels would be allowed (e.g., every other day, once a week, et cetera).
In addition, since you stated that the tongue swelling was “marked,” I would also suggest supplying the family with an automatic epinephrine injector.
Thank you again for your inquiry and we hope this response is helpful to you.
Angioneurotic edema with risperidone: a case report and review of literature
General Hospital Psychiatry
Volume 32, Issue 6, November–December 2010, Pages 646.e1–646.e3
Angioedema is characterized by oedema of the deep dermal and subcutaneous tissues and is reported as a rare adverse cutaneous reaction with risperidone, clozapine, ziprasidone, droperidol and chlorpromazine. Here we report a case of angioedema with risperidone. A 15-year-old boy diagnosed with schizophrenia was started on risperidone 1 mg/day, which was increased to 2 mg/day after 2 weeks. Within a week of increasing risperidone, he developed swelling over the face and feet. On examination he was found to have periorbital oedema and swollen lips. Following this, risperidone was stopped. Over the period of 1 week his oedema subsided, following which he was started on Haloperidol 5 mg/day, with which his psychosis improved significantly
 Cooney C, Nagy A. Angio-oedema associated with risperidone. BMJ 1995;311:1204.
 Kores Plesnicar B, Vitorovic S, Zalar B, Tomori M. Three challenges and a rechallenge episode of angio-oedema occurring in treatment with risperidone. Eur Psychiatry 2001;16:506–7.
Phil Lieberman, M.D.