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This history was consistent with a phototoxic reaction. Patch tests were performed according to International Contact Dermatitis Research Group guidelines, using Finn Chambers (Epitest Ltd Oy, Tuusula, Finland) on Scanpor tape (Norgesplaster A/S, Vennesla, Norway). The patient was patch tested with the Portuguese Contact Dermatitis Group baseline series and with rue diluted to 1%, 2%, 5%, and 10% in pet. Results were read at D2; only a non-relevant reaction to thiomersal (þþ) was observed. The child was treated with a liquorice extract-based skin lightening cream and a broad-spectrum sunscreen with instructions to avoid exposure to sunlight. Four weeks after the initial clinical presentation, only a very slight hyperpigmentation over the affected areas remained.
Comment
Phytophotodermatitis due to homemade ointment for Pediculosis capitis Contact Dermatitis 2008: 59: 373–374
Paulo Morais1, Alberto Mota1,2, Ana Paula Cunha1,2, Lı´gia Peralta3 and Filomena Azevedo1 1
Department of Dermatology and Venereology, Hospital S. Joa˜o, 2Faculty of Medicine, University of Porto, Porto, and 3Department of Pediatrics, Hospital Infante D. Pedro, Aveiro, Portugal Key words: phototoxicity; phytophotodermatitis; psoralens; rue; Ruta graveolens.
Case Report An 8-year-old girl presented with a berloque pattern consisting of pendantlike streaks of macular hyperpigmentation on her neck and upper chest (Fig. 1a and b) 2 days after the application of a homemade ointment containing rue (Ruta graveolens, Fig. 1c) for the treatment of Pediculosis capitis. She was exposed to the sun after the application of this product and denied erythema or blistering before the hyperpigmentation developed.
Phytophotodermatitis is a common cutaneous phototoxic inflammatory eruption resulting from contact with plant-derived (phyto), fruit-derived, or vegetable-derived photosensitizing compounds, such as furocoumarins (psoralens), followed by exposure to sunlight (especially ultraviolet A, 320–400 nm range of the spectrum) (1–3). R. graveolens, or garden rue, is a well-recognized cause of phototoxic reactions, including in children. It belongs to the Rutaceae family, which includes other phototoxic members such as citrus fruits (2, 4, 5). The phototoxic compounds of rue are the furanocoumarins 5-methoxypsoralen (bergapten) and 8-methoxypsoralen (xanthotoxin) and the quinoline alkaloids dictamnine and graveoline (6, 7). This herbal plant has a long history as a folk medicine remedy including as an insect repellent, abortive, and protective against evil spells (8–10). However, to the best of our knowledge, the use of rue for the treatment of head lice had never been reported in the literature. We describe here an unusual case of phytophototoxicity induced by R. graveolens. We draw attention to the particular and unreported pattern of presentation evidenced in our patient, resembling that observed in the classic perfume-induced berloque dermatitis. Physicians should be aware that an initial inflammatory reaction may be subtle or unrecognized
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Fig. 1. Streaky hyperpigmentation on the neck and upper chest in a berloque-like pattern (a and b). Ruta graveolens (c).
by the patient and, as it was the case of our patient, only hyperpigmentation is evident (5, 11).
References 1. MacFarlane D F, DeLeo V A. Phototoxic and photoallergic dermatitis. In: Practical Contact Dermatitis: A Handbook for the Practitioner, Guin J D (ed): New York, McGrawHill Inc, 1995: pp. 83–92. 2. Cather J C, Macknet M R, Menter M A. Hyperpigmented macules and streaks. Proc (Bayl Univ Med Cent) 2000: 13: 405–406. 3. Klaber R. Phytophotodermatitis. Br J Derm Syph 1942: 54: 193. 4. Pathak M A. Phytophotodermatitis. Clin Dermatol 1986: 4: 102–121. 5. Lovell C R. Plants and the Skin, 1st edition. Oxford, Blackwell Scientific Publications, 1993. 6. Schempp C M, Scho¨pf E, Simon J C. Dermatitis bullosa striata pratensis durch Ruta graveolens L. (Gartenraute). Hautarzt 1999: 50: 432–434. 7. Hale A L, Meepagala K M, Oliva A et al. Phytotoxins from the leaves of Ruta graveolens. J Agric Food Chem 2004: 52: 3345–3349. 8. Wessner D, Hofmann H, Ring J. Phytophotodermatitis due to Ruta graveolens applied as protection against evil spells. Contact Dermatitis 1999: 41: 232. 9. Heskel N S, Amon R B, Storrs F J, White C R. Phytophotodermatitis due to Ruta graveolens. Contact Dermatitis 1983: 9: 278–280. 10. Gawkrodger D J, Savin J A. Phytophotodermatitis due to common rue (Ruta graveolens). Contact Dermatitis 1983: 9: 224. 11. Eickhorst K, DeLeo V, Csaposs J. Rue the herb: Ruta graveolens – associated phytophototoxicity. Dermatitis 2007: 18: 52–55.
Address: Paulo Morais, MD Department of Dermatology and Venereology Hospital de S. Joa˜o Alameda Professor Hernaˆni Monteiro
4200-319 Porto, Portugal Tel: (þ351)225512193 Fax: (þ351)225512193 e-mail:
[email protected]
