Sea urchin injuries are caused by contact with sea urchin

Sea urchin

Sea urchins or urchins are small, spiny, globular animals which, with their close kin, such as sand dollars, constitute the class Echinoidea of the echinoderm phylum. They inhabit all oceans. Their shell, or "test", is round and spiny, typically from across. Common colors include black and dull...

s, and are characterized by puncture wounds inflicted by the animal's brittle, fragile spines.

Process

Sea urchin spines can be poisonous or cause infection. Granuloma

Granuloma

Granuloma is a medical term for a tiny collection of immune cells known as macrophages. Granulomas form when the immune system attempts to wall off substances that it perceives as foreign but is unable to eliminate. Such substances include infectious organisms such as bacteria and fungi as well as...

and staining of the skin from the natural dye inside the sea urchin can also occur. Breathing problems may indicate a serious reaction to toxins in the sea urchin.