Now about Pannakkal's reply. Thank you very much for you suggestion. I just don't know what means intercurrent(?).
I looked in Materia medica on the remedies you listed and the most apealling to me is Aurum metallicum. The interesting thing that stands for aurum is that "in symptom picture of aurum are disoders resembling the symptoms of mercury poisoning affecting ... glands". ( I always think my son got some mercury from my amalgalm feelings during nursing).Also for aurum stands some characteristics, that fits my son:irritability, photophobia, oversensitive to noise, pain and swelling of testicles.
it happend,that I read today in Michael Weiner's "Complete book of homeopathy" an interesting case of study of undescended testicle. Unfortunatly, it does not document the symptoms upon which doctor prescribed.