Pietro Verni

Dermatitis caused by Coelenterates

The phylum of Coelenterata (Cnidaria), animals that have a worldwide distribution, includes four toxic classes: Anthozoa (sea anemones, true hard and soft corals and sea pens), Scyphozoa (true jellyfish), Hydrozoa (physalia and fire corals: not true corals), and Cubozoa (box jellyfish). Highly specialized cells (nematocytes) are present on the surface of Coelenterata, and associated with the venom discharged during stings. An organ synthesized by the nematocytes, the nematocyst, is expelled in a harpoon-like fashion during a nanosecond process, and injects different active toxic substances into the prey. Injuries caused by cnidarians are of two pathogenic orders, toxic (the most common mechanism) and allergic (of immediate or delayed type). Different clinical pictures can arise after Cnidarians envenomations, featuring skin and systemic reactions that can even be fatal. True jellyfish induce a great number of accidents in the world, although they are generally less severe than those caused by box jellyfish and physaliae. Box jellyfish are among the most significant toxic marine animals, and their envenomation usually presents as a medical emergency. Sea anemones can cause cutaneous and systemic manifestations, including seabather’s eruption, characterized by pruriginous papulous lesions that persist for 1–4 weeks. True corals provoke skin lesions through toxic and traumatic mechanisms. Physaliae stings are usually painful and severe, and go together with systemic manifestations that can involve various organs. Reactions to fire corals are also very severe. A correct diagnosis and appropriate treatment are essential in cases of cnidarian envenomations, particularly because specific antivenoms are lacking.

In vitro effects of polyphenols on the peripheral immune responses in nickel-sensitized patients

BACKGROUND Nickel (Ni) is a metal largely present in the environment and prolonged exposure to it may lead to multiple pathological conditions in human subjects. Among these, the most frequent is allergic contact dermatitis. METHODS Peripheral blood mononuclear cells isolated from 25 patients with Ni-dependent contact dermatitis were evaluated in terms of cytokine release and nitric oxide (NO) production in the presence or absence of two doses (3 and 5 µg, respectively) of polyphenols. RESULTS Polyphenols were able to reduce the increased release of interferon-γ and interleukin (IL)-4, while maintaining the equilibrium between IL-10 and IL-17. At the same time, exaggerated release of NO was reduced by polyphenol supplementation. CONCLUSION In view of their anti-inflammatory activities, polyphenols may represent a potential therapeutic tool to treat Ni-sensitized patients.

Dermatitis caused by Echinoderms

There are about 80 species of toxic or venomous Echinoderms. In particular, sea urchins, with their spine-covered bodies, are poisonous and can induce various types of reaction in man both when eaten as seafood and when they sting. In the first case, because of the toxins present in their gonads, the symptoms, although rarely fatal, will include gastrointestinal disorders and allergic reactions. Contact with the spines, that are sharp and very fragile, induces immediate and delayed reactions. Penetration of the spines into the skin causes immediate, burning pain, followed by erythema and edema, and there may be abundant bleeding from the affected part. Systemic symptoms can also develop, including nausea, muscle cramps, and respiratory distress. These symptoms can last up to 1–2 weeks, provided that the spines are immediately and completely removed. Delayed reactions are notoriously nodular granulomatous lesions, mostly considered to be non immunological reactions to a foreign body. Starfish can induce an urticarial clinical picture due to their toxins released in the water, as well as nodular granulomatous lesions after contact with the spines, that can be associated with very severe systemic symptoms. Again as a result of a toxic substance released into the water, seacucumbers can induce an irritant contact dermatitis and ocular lesions that can even end in blindness.

Other Nontuberculous Mycobacteria and Skin Infection

Various other mycobacteria can be pathogenic for man [1–6]. Here, those that most often induce skin manifestations will be considered. These complaints, too, are to be considered non contagious, since person-to-person transmission has never yet been documented [4, 7].

Nontuberculous Mycobacteria and Skin Infection

The current high level of interest in disease induced by nontuberculous mycobacteria (NTM) is due not only to the frequent association with AIDS, but also to the strong evidence of pulmonary and extrapulmonary diseases in the general population [1–12]. Moreover, NTM infections are emerging in previously unreported sectors, and exhibiting new clinical manifestations. Undoubtedly, the increased evidence of the disease is also attributable to methodological improvements in mycobacteriology laboratories, that have enabled the isolation and rapid, accurate identification of the various species and the clinical characteristics of some peculiar clinical pictures [7].

Rapidly Growing Mycobacteria and Skin Infection

Rapidly growing mycobacteria (RGM) are among the most common nontuberculous mycobacteria (NTM) associated with cutaneous infections in industrialized countries [1–8].

Mycobacterium scrofulaceum Infection

Mycobacterium scrofulaceum is a member of the Runyon class II scotochromogen acid-fast bacilli [1–3]. It is widely present in nature, but is now an infrequent human pathogen. It was first described in the 1950s [4–6] and the name likely derives from its isolation from cervical lymph nodes.

Aquatic Skin Diseases from Chemical and Physical Causes

Various dermatological conditions with physical and chemical causes are connected with salt- or freshwater. Aquagenic urticaria, induced simply by skin contact with the water, regardless of its physical and chemical properties, starts some minutes after the contact and resolves after about an hour: the lesions are intensely itchy and punctiform. Cold urticaria, that features skin or mucosal pomphoid lesions that develop after contact with cold water or after the ingestion of cold drinks or foods, presents under various guises: familial or acquired, immediate or delayed, localized or systemic, primitive or secondary. Aquagenic pruritus manifests during bathing or immediately after coming out of the water and lasts some minutes or hours; in many cases it is observed in patients with polycythaemia rubra vera. Prolonged immersion in seawater causes electrolytic alterations due to percutaneous absorption (“immersion syndrome”). Swimmers, hydrotherapists, physiotherapists, cleaners and swimming pool attendants present dehydration of the skin and hair because of the chlorine and bromine compounds used to disinfect the water. Both professional and amateur scuba divers are exposed to a variety of risks including skin complaints. An occupational chronic traumatic scleroedema of the hands, of various etiologies, is frequently observed in fishermen; the complaint, that can also affects the forearms, can persist for many years after abandonment of the work activity.

Dermatitis caused by sponges

Sponges, members of the Porifera phylum, normally lie stationary attached to the sea bottom or sometimes the lake bottom. There are 5000 known species of sponges, which vary greatly as to shape, size and colour, ranging from practically invisible to 2 m in length and from pastel tones to bright hues: red, yellow, orange and blue [1, 2].

Dermatitis Caused by Algae and Bryozoans

Algae and Bryozoans can cause various clinical pictures. Algae are found in all aquatic environments. Some species of Cyanophyceae (“blue-green algae”) and Dinophyceae classes, present in salt and freshwater, produce one or more toxins, some of which are strongly neurotoxic or hepatotoxic, while others provoke gastroenteritis and skin disorders. The skin toxicity can manifest in humans with irritant and allergic reactions. A particular alga of the Cyanophyceae, present in various localities of Australia, Florida and Hawaii, periodically induces the so-called swimmer’s itch, a dermatitis whose onset occurs a few minutes after bathing, with intense itching and burning sensations, followed after 3–8 h by blisters leaving painful erosions in the areas covered by the swimming costume. Skin protothecosis is another infection induced by seaweed, that mainly affects immunocompromised subjects, triggering various clinical pictures. The affliction, reported in various parts of the world, is difficult to diagnose. The lesions can persist for years and there is no known elective treatment. Bryozoans (moss), belonging to the animal kingdom, can cause quite a disabling contact dermatitis in fishermen, featuring dry, fissuring and exudative lesions of the hands and forearms. The complaint, that may also be of an allergic nature, can become generalized.