Dermatitis caused by sponges

It has long been known that sponges, the most primitive pluricellular organisms, are not entirely innocuous. Some species can, in fact, cause serious skin reactions, induced by the spicules on the horny skeleton or by the toxins present on their surface or secreted into the water. Clinical manifestations due to stings of sponges may be immediate or delayed. A few minutes after the contact, prickling, stinging or burning occur, followed by pain, erythema, swelling and stiffness. The dermatitis progresses to papulo-vesicular or bullous eruptions with a serous or purulent exudate. The onset of the affliction may occur even many days after the contact. Some species of sponges can also provoke much more violent reactions, and unless they are adequately treated such complaints may persist for several months. Apart from the above-mentioned contact dermatitis from chemical agents, some sponges can induce traumatic dermatitis after contact with the spicules, which penetrate the skin and cause foreign-body reactions. The spicules of fresh water sponges float in suspension in the water and provoke a generalized erythematous papular eruption, that can result in possible blindness in some cases. It is important to bear in mind that subjects with early signs of a reaction immediately after the contact should be warned of the risk of delayed effects as well.