First Aid for SPONGE STINGS
For uncomplicated sponge stings, rinse and dry the area, then lift skeletal spikes from the skin with adhesive tape. You may not be able to see these tiny cactus-like spikes. Other treatments for sponge stings are unproven. In some cases, soaking the area in vinegar or rubbing alcohol seems to relieve pain. After soaking, try 1 percent hydrocortisone ointment four times a day, and one or two 25 milligram diphenhydramine (Benadryl) tablets every 6 hours. These drugs are sold without prescription. Diphenhydramine may cause drowsiness. Don't drive, swim, or surf after taking this medication. Tetanus (lockjaw)-causing bacteria lives in some sponges. Make sure tetanus immunization is up to date. (See Staph, Strep and General Wound Care for information on tetanus immunization.)
Infections can develop after sponge stings. If blisters fill with pus, or the red area spreads and feels warm, see a doctor.
Any difficulty breathing or a generalized body rash after a sponge sting is always a medical emergency.