It's probably a fungus. Read http://www.caudata.org/cc/articles/sores.shtml and http://www.caudata.org/cc/articles/salt.shtml and these should help you.
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1.1.2 Python regius
0.0.1 Eunectes notaeus
0.0.1 Lampropeltis spp.
5.0.0 Ambystoma mexicanum
1.3.0 Triturus karelinii
1.3.0 Taricha granulosa
0.3.0 Ambystoma jeffersonianum
0.0.3 Salamandra salamandra
0.0.1 Tylototriton verrucosus
1.0.0 Grammastola cala
1.0.0 Homo sapiens 'Hottie'