scats have venom in little sacs under their dorsal spines. It can cause inflammation and a great deal of pain to people so I gather it would cause some discomfort to fish. If people get stung in the neck, face or chest area the inflammation can restrict breathing and medical treatment will be required.
The venom is protien based and breaks down quicker in warm conditions. If you are stung you immerse the affected area in hot water, (not too hot otherwise you burn yourself) and leave the stung area there for as long as possible, (an hour or two helps).
However, fish have evolved to eat each other and they should have some tolerance to the venom from poisonous fishes.
If the cichlid was stung more than 24 hours ago and it is still alive now it should be fine. If it only just happened try incresing the temp a couple of degrees (but don't make the tank warmer than 30C). And increase aeration.