DCS or toxin exposure?

[rickmorgan2003]

So here's my stupid story from last October:
5 days of diving grand bahamas. Kept well withing no deco limits never exceeding 3 bars out of 5 on my nitrogen load graph on the computer. 2 tanks a day. with the exception of day one where we dove to 90 feet, the rest of the trip was no deeper than 63. On the last dive my boat captain stated he would be diving to help restore a sponge garden that was damaged by storms, transplanting sponges broken off the reef to a new location. While diving I noticed a stove pipe sponge floating around the sandy bottom and carefully picked it up by the base/rock and brought it over to him. He had gloves, I didn't.
At the end of the dive I noticed my hand hurt a little and it looked like a little rash was on the palm surface of hand and fingers. I didn't do a full grasp of the sponge and believed the sponges did not sting so started questioning what I picked up. My buddy the day before caught a small Jelly across and exposed area so I thought maybe that was the case.
Didn't hurt much so didn't worry. Flight home late the next day-24 hours surface time- computer said safe to fly: Both hands started hurting more and rash became more pronounce. Day after that- really hurt, rash and mottling more pronounced and joint pain, swelling and stiffness and an itch that felt like it was deep under the skin vs. a skin rash itch. I was tired but no more so than expected after 5 days of diving. No other DCS symptoms, stayed on hands but I thought it was weird that it was both hands, I didn't remember touching the sponge with more than my right hand.
Went to MD, they said it was probably an allergic reaction to the sponge and put me on high dose steroids. Swelling went down after a few days and pain slowly diminished over the week. I did some research into sponges, there are three varieties that can sting so I chalked it all up to being stupid and touching critters when I know I shouldn't.
Kids were taking a open water course and DI talked about mild DCS and it made me think about that last trip. I know I was within my limits but that doesn't guarantee you won't get DCS. The severity increase during flight became a red flag in my mind. Also, what are the chances that the sponge I grabbed was one of the very few that could sting. The MD I saw has no dive medicine training- just a local Kaiser doc so she could very easily miss it. Symptoms did gradually improve with steroids/time.
So-was it a mild DCS experience or was it the sponge?

[DevonDiver]

Moderator's Comments:

Moved to the Diving Medicine forum, due to specific nature of the OP's post

[TSandM]

Given that your dives were as described, and assuming no ascent violations, the nitrogen loading was moderate. Hands are not a common site for DCS symptoms, and although a skin rash can be a manifestation of DCS, it typically occurs on the torso, in areas of thick subcutaneous fat. In addition, DCS symptoms occurring in the same area bilaterally are unusual. Since your hands were uncovered and are the most likely part of your body to come in contact with something, I'd say this was likely to be a contact dermatitis of some kind, perhaps from the sponge, or perhaps from something else you weren't even aware of touching at the time you did it. Any ascents up a line?

[Duke Dive Medicine]

Concur with Lynne. Sounds like sponge spicules rather than DCS.