Nephew away at college had a bout of poison ivy recently. He developed a quarter size lump on the side of neck. Also having intermittent headaches which cause vomiting, fatigue and occasional diarrhea. He was treated at Urgicare and given antibiotics for poison ivy. No blood test or other tests done. This doesn`t sound like just poison ivy. He sent a pic of lump and there isn`t any poison ivy rash on his neck. Just well defined quarter size lump. He was told to take antibiotics and if lump doesn`t clear to see his family Dr when he is home for Labor Day. We suspect swollen lymph node. Is that possible from poison ivy?