Members of this family, natives of tropical America and the West Indies, number some 1400 species in 44 genera. Typically, they are spiny rosette-forming plants, many of which grow terrestrially, but most of which are epiphytes in their natural environment. Because of the peculiar arrangement of their leaves, many of the rosette-forming species in the tropics are often found associated with a varied fauna including ants, spiders, and scorpions (Wheeler 1942).
Several species produce edible fruits, the best known of which is the pineapple, from Ananas comosus Merrill, which is an important article of commerce.
Tillandsia usneoides L. is an unusual bromeliad. It hangs from branches in long grey festoons that resemble certain lichens. The plant is known by a variety of common names including long, Florida, Louisiana, or Spanish moss, old man's beard, and vegetable horsehair. It is used for stuffing pillows and similar such items (Willis 1973, Usher 1974).
Members of this family are occasionally grown as house or greenhouse plants. Most commonly grown are Aechmea Ruiz & Pavón, Billbergia Thunb., and Vriesea Lindl. mut. Beer species.
The most likely hazard associated with members of this family is mechanical injury caused by the strong, sharp, curved spines that adorn the leaf edges of many species. In addition, persons coming into contact with the plant sap of some species may develop an irritant dermatitis from the proteolytic enzymes that are present. Tillandsia L. species in particular, when growing in the wild, may cause a pseudophytodermatitis when handled. This is because they provide nesting sites for ants which, depending on species, may bite or sting aggressively if the plant is disturbed.
An herbarium specimen of this species was described as being a "small, wasp-inhabited plant" (von Reis & Lipp 1982).
Ants nest among the aerial roots of this species in its natural habitat (Wheeler 1921).
"Pineapple estate pyosis", occurring in workers who gather the fruits, probably represents an acarus infection with secondary bacterial infection (Simons 1953).
The raw fruit, when eaten in large quantity, produces a burning sensation of the lips and mouth (Watt & Breyer-Brandwijk 1962) and can also produce angular stomatitis (Fasal 1945).
Almost complete obliteration of the fingerprints by removal of the stratum corneum in workers employed in cutting up pineapples has been ascribed to the effects of pressure together with the keratolytic effect of bromelain, a protease found in the plant sap. A variety named Mauritius pineapple seemed to be most injurious. The nails were unaffected, in contrast to the nail damage that occurs in workers exposed to proteases of animal origin. Calcium oxalate and citric acid were excluded as causes of the skin changes. Moniliasis of the finger webs was occasionally observed in pineapple cutters (Polunin 1951).
The proteases in this species are glycoproteins and are related in their properties to papain. The different parts of the plant yield slightly different proteases, and each may be further fractionated into its constituent proteolytic enzymes. Thus, stem bromelain, fruit bromelain, and leaf bromelain have been studied (El-Gharbawi & Whitaker 1963, Murachi 1970, Daley & Vines 1978).
Pineapple fruits contain ethyl acrylate. Ethyl acrylate (4% in petrolatum) produced sensitisation in 10 of 24 subjects in a maximisation test (Opdyke 1975). A positive patch tests reaction to pineapple in a fruit handler (Morris 1954) cannot be interpreted in the absence of controls.
The strong sharp recurved hooks on the leaves can inflict mechanical injury (Allen 1943).
Bongiorno de Pfirter & Buttazzoni de Cozzarin (1976) isolated a protease named balansain from the fruit juice of this plant. Balansain was found to contain at least 6 constituent proteins, and to resemble papain in its properties.
If eaten without peeling, the fruit irritates the lips (Morton 1981).
Del Castillo & Castañeda-Agulló (1974) isolated the proteases hemisphericain, karatasain, palmerain, and sylvestrisain respectively from the above species. Each was found to consist of several component proteins.
Bromelia karatas is often grown as a barrier hedge, impassable by animals and humans (Morton 1981).
This species is often planted for hedges, its spiny leaves serving well to repel animals (Standley 1937a). Recurved hooks on the leaf margins can produce mechanical injury (Allen 1943, Oakes & Butcher 1962).
The fruit is eaten in Central America without ill effects other than mild irritation around the mouth on the upper part of the lips (Asenjo et al. 1944). The fruit juice is pleasantly acid, but produces a burning sensation when applied to the skin or lips, followed by peeling after a few hours (Asenjo & Capella de Fernandez 1942). Small painful ulcers readily developed within a period of 3–6 h on the fingertips of laboratory workers who handled the pulp of the fruit without rubber gloves. This was apparently the result of a combination of mechanical irritation caused by calcium oxalate raphides (of average size 108 μm in length and 5 μm in width) and subcutaneous injection of proteolytic enzyme (Asenjo et al. 1944).
A protease named pinguinain may be isolated from the fruit. In a Puerto Rican variety, pinguinain has been found to be a single compound (Toro-Goyco & Matos 1964), whilst in a Cuban variety is has been found to consist of at least two components (Messing 1961). Pinguinain is a glycoprotein that resembles papain in its properties, but is unusual in being very resistant to heat denaturation and has an optimum activity at 65°C (Toro-Goyco et al. 1968).
The spines of the edible fruits can produce mechanical injury (Burkill 1935).
Ants nest amongst the aerial roots of this species in its natural habitat (Wheeler 1921).
[Information available but not yet included in database]
The following species have been reported to provide, in their natural habitat, nesting sites for ants thus rendering them potential dermatological hazards:
Tillandsia species constitute the great bulk of the epiphytic flora in the West Indies (Wheeler 1942).