Phytophotodermatitis

Two clinical presentations exist for phytophotodermatitis (PPD or simply photodermatatis), however berloque dermatitis is only associated with psoralens in perfumes, so dermatitis bullosa striata pratensis will be considered here. There are four plant families associated with bullosa striata pratensis. Members of the Umbelliferae family are the most common causes of PPD and include wild parsnip (Pastinaca sativa), cow parsnip (Heracleum maximum), and wild carrot (Daucus carota). Bergamot orange, lime, and the gas plant are members of the Rutaceae family, which is the second most common cause of PPD in the United States. Although rare in the United States, the remaining two families are more prevalent elsewhere in the world. Figs and other Ficus species are members of the Moraceae family, and the Pso-ralea species are members of the Leguminosae family (41).

The active agents in these plants that cause PPD, are various furo-coumarins (psoralens), which are natural photosensitive substances that are activated by ultraviolet light. Psoralens are contained in a plant's sap, which can come in contact with a person's skin with varying degrees of difficulty. The substance remains inactive on the skin until exposed to sunlight. Following sun exposure, an uncomfortable rash develops. It closely resembles the rash associated with poison ivy dermatitis, however it occurs only in areas exposed to the sun. The rash is characterized by burning and painful sensations, vesiculation, and erythema. Unlike poison ivy rashes, PPD rashes do not resolve as quickly. The rash can develop shortly following plant and sun exposure but may last from 1 to 2 weeks, leaving behind streaky hyperpig-mentations on the skin that can remain for several months. Treatment of PPD is similar to AACD in that all that can be achieved is the relief of symptoms. As with all other forms of dermatitis, a person should promptly wash any surfaces that are presumed to have been exposed to any plant products that could be potentially harmful (49).

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