Tulipalin A induced phytotoxicity

Abstract

Tulipalin A induced phytotoxicity is a persistent allergic contact dermatitides documented in floral workers exposed to Alstroemeria and its cultivars.[1] The causative allergen is tulipalin A, a toxic glycoside named for the tulip bulbs from which it was first isolated.[2] The condition is characterized by fissured acropulpitis, often accompanied by hyperpigmentation, onychorrhexis, and paronychia. More of the volar surface may be affected in sensitized florists. Dermatitis and paronychia are extremely common conditions and diagnostic errors may occur. A thorough patient history, in conjunction with confirmatory patch testing with a bulb sliver and tuliposide A exposure, can prevent misdiagnosis. We report a case of Tulipalin A induced phytotoxicity misdiagnosed as an unresolved tinea manuum infection in a patient evaluated for occupational exposure.

INTRODUCTION

Adverse reactions resulting from recreational and occupational plant exposures are fairly ubiquitous.[3,4,5,6] Injuries range from mild respiratory complaints, phytodermatitis, irritant contact dermatitis, and allergic contact dermatitis to toxin-induced injuries and mechanical damage.[7] Tulipalin A induced phytotoxicity, also Tulip Fingers and Alstroemeria dermatitis, is a common occupational allergy in floral workers exposed to Tulip and Alstroemeria cultivars. Similar phytotoxicity results from allyl isothiocyanate compounds present in the Cruciferae plant family.[3,8] Tulipalin A (a-methylene-g-butyrolactone) and its parent compound tuliposide A (a-methylene-g-hydroxybutyric acid) are concentrated in the outer layers of the plant bulbs and the pistils. In the plant, they are protective antibiotics exerting a fungicidal effect in flower bulbs.[9,10] Both compounds were evaluated along with 240+ chemicals for inclusion on the ‘Allergen List’ compiled by Germany's Federal Institute for Risk Assessment (BfR). They were assigned to Category B: Solid-based indication for contact allergenic effects, because there is evidence of contact allergenic effects in animals and humans as well as induction of cross reactions in humans.[11] They can also be considered skin sensitizers because under The Globally Harmonized System for Classification and Labeling of Chemicals (GHS), a human skin sensitizer is “a substance that will induce an allergic response following skin contact”.[12,13]

Although there are multiple forms of dermatitis, the clinical presentation is often similar.[3] Common symptoms include erythema, pruritus, edema, lichenification, and vesiculation. This may make accurate diagnosis challenging. Tulip Fingers and Alstroemeria dermatitis, the latter in particular due to the popularity of the inexpensive Alstroemeria in lower cost floral arrangements, should be considered as a differential diagnosis in cases of unresolved dermatitis in floral workers.[2,14] In this article we highlight the importance of comprehensive patient histories in a case of Tulipalin A induced phytotoxicity misdiagnosed as a tinea manuum infection in an individual with suspected occupational fungal exposure and a review of the relevant scientific literature necessary to evaluate risk factors for the disease.

CASE REPORT

An immunocompetent 30-year-old female, was referred for a medical examination to assess persistent unresolved tinea manuum, possibly related to occupational fungal exposure. The patient complained of “little bumps” on the dorsal surface of her right index finger around the distal interphalangeal joint. The bumps erupted across the dorsal surface of her right hand between digits #1 and #2, progressed up to her wrists, popped, dried, and flaked off the residual skin. The condition recurred several times over the next few months.

All physical examination outcomes were normal with the exception of lichenification and peeling of multiple fingers, including the palmar and dorsal surface, ulcers on several fingertips of each hand, pain, and discoloration of hands. Apart from the ongoing issue with her hands, the patient's medical history was unremarkable. No one in her immediate family has any history of persistent dermatologic complaints.

The patient was initially diagnosed with tinea manis and prescribed a lengthy course of prescription antifungal treatment in 2010 after a nail culture indicated yeast, later identified as Cryptococcus. Tinea manis is unlikely, given the absence of the characteristic ring-like pattern. The presence of a Cryptococcus species was likely a skin contaminant as it is unlikely that she would have an infection since the vast majority of Cryptococcal infections occur in immunocompromised individuals. The antifungal medication did not significantly change the course of the disease process. The lesions seem to worsen over time, and then get better. Over time, the skin on her finger pads has thinned greatly. She has resorted to wearing a band-aid over her right index finger tip because it is continuously tender and depigmented. At night, the dorsal surfaces of her fingers seem to itch a great deal with no relief. The patient was instructed not to wear gloves at work because the gloves reportedly “trap” the fungus underneath and expose her skin.

The patient mentioned that she works a great deal with the ornamental plant and flower Alstroemeria, which has a moderate literature database detailing cases of persistent allergic contact dermatitis in florists. As previously noted, the causative allergen is known as tulipalin A (α-methylene-γ-butyrolactone). The glycoside and its parent compound are named for the tulip bulbs from which they were originally derived. There is also a moderate literature database describing “tulip fingers”, an allergic contact dermatitis found in tulip workers primarily in the Netherlands. Interestingly, areas of depigmentation often follow the characteristic lesions that are similar to the initial bumps that this patient reported at the first visit.

The patient was instructed to wear nitrile gloves at work, as her condition is not a fungal problem. She should not wear vinyl gloves, as the causative allergen crosses every type of common gloves except nitrile. She was referred to a dermatologist who may elect to take a skin biopsy and/or perform patch testing. Diagnosis of tulipalin A induced phytotoxicity requires patch testing with the routine TRUE TEST, as well as a number of plant extracts including: Sesquiterpene lactone mix 0.1%, parthenolide 0.1%, 2,6-ditert-butyl-p-cresol 2%, and at least one preparation of tulipalin A.

DISCUSSION

First described as ‘tulip fingers’ in the European tulip industry, tulipalin A induced phytotoxicity results in severe dermatitis. Similar phytotoxicity, termed Alstroemeria dermatitis, has been described in florists who use Alstroemeria.[15,16] Contact with plants containing tulipalin A may result in persistent allergic contact dermatitis.[1,17] It is a common occupational complaint in floral workers who handle Alstoemeria and Tulip cultivars.[5,18] The toxin is most concentrated in the flower bulbs and stems, although smaller amounts may be found in other parts of the plant.[2,10]

Effects of tulipalin A exposure may be immediate or delayed.[19] Manifestations of phototoxicity include pruritus and edema in the fingers and along the palmar surface of the hand. Lesions develop and gradually exfoliate. Repeated exposures may lead to significant thinning of the skin and pigmentation changes.[20] Paronychia is commonly seen along with nail splitting and ulceration of the nail bed in more severe cases.[21] Patients typically report significant pain associated with the outbreaks. Sensitive individuals may also develop rhinitis following airborne exposures.[22,23] Facial swelling may result if the worker touches their face after handling the bulbs. The only effective treatment is to reduce contact with tulipaside and using nitrile gloves.[15] Vinyl gloves are not an effective barrier.

CONCLUSION

Differentiating tulipalin A induced phytotoxicity from the innumerable other dermatoses makes diagnosis difficult.[24] A suspected case of contact dermatitis requires meticulous history taking and physical examination.[11] Typically, a sensitized individual will develop acute symptoms 12-24 h after any subsequent exposures.[6] Patch testing is used to demonstrate contact with the allergenic tulipaside A.[7,25] Given the occupational history of this patient, a diagnosis of tulipalin A phytotoxicity is far more appropriate than tinea manis or Cryptococcus. Follow-up with a dermatologist for skin biopsy and/or patch testing with TRUE TEST is recommended.