Airborne Contact Dermatitis From Coleus Plant

Lars Erik Bryld

A 66-year-old woman with a 25-year history of facial dermatitis and no obvious external cause was patch tested with her houseplants and a wide range of

P LANTS of the genus Colew originate from Africa and tropical Asia and have been used as

houseplants for many years. Its multicolored leaves contain line hairs, which may be an irritant. A strong allergen, Coleon 0 (Fig. l), is present in large amounts.’ Nevertheless, sensitization seems to be a rare event, and only a few cases are described in the literature.

CASE REPORT

A 65-year-old woman was referred in August 1995 with dry, scaly, and erythematous skin on the eyelids and periorbital regionwith extension to the face and neck. These symptoms had been present for many years and were seen as a mild psoriasis because of to a palmoplantar rash 25 years ago and a tendency to mild external otitis. Symptom intensity had increased during the preceding 4 years since retirement. When at its worst, swelling of the eyelids and diffuse facial dermatitis was prominent. No suspicious activities were reported, but the patient had a considerable collection of houseplants.

Extensive epicutaneous testing and skin prick tests were performed. Allergens were dissolved in petrolatum or water, occluded under Finn Chambers (Epitest, Finland), fixed with Scanpore Tape (Norgesplaster, Norway), and placed on the back for 48 hours. Evaluation of the skin was made when allergens were removed on day 2, and furthermore on day 3 and day 7. Patch tests included the European standard patch series, our department’s screening series for common ingredients in cosmet- ics and topical drugs (eg, preservatives), the patient’s own skin products, and previously used topical medicine. Skin prick tests included different pollens, household animals, and food ingredi- ents. None of these tests showed any reaction.

Pieces of stem, leaves, and flowers from all of the patient’s plants were finally placed on the back without any processing. Reactions of erythema, infiltration, and papules were seen on day 3 and day 7 from all constituents of Coleus blumei, whereas no reaction was seen from 24 other plants tested likewise. The reactions were regarded as weak definite positive reactions (+) according to recommendations from the Interna- tional Contact Dermatitis Research Group.2 Five control per- sons were tested with parts from the Cobllr plant in the same

From the Department of Dennatologv, lJniuersi& of Copenhagen, Gentofie Hospital, Denmark.

Address unwponaime to Lars Erik Bvld, MD, Department of Dermatology, Gentoft Hospital, NieLr Andersenr Vej 65, DK-2900 Hellerup, Denmark.

Copyright 0 19976y WB. Saunders Company

104~199Xl97/0801-0004$03.00l0

common allergens. The only positive reaction found was to the plant Coleus blumei. Copyright o 1997 by W.B. Saunders Company

manner as with our patient. Apart from one doubtful reaction on day 2, which cleared in a few hours, none of these controls produced irritant or allergic reactions.

Apart from the previously mentioned palmoplantar rash, the patient never had skin changes on the hands or forearms, despite daily handling of her plants. After the removal of three coleus plants from the home, her facial rash gradually improved.

DISCUSSION

The genus Coleus comprises approximately 150 species, several of which are common house- plants (Fig. 2).’ The first reference to a skin reaction to coleus plant is in a review of exogenous dermatitis with a comprehensive list of skin irri- tants.3 The author had observed dermatitis in one patient on skin directly exposed to the plant. Three case reports in the preceding 20 years have men- tioned coleus dermatitis. All of these had a pattern of airborne contact dermatitis with facial rash and eyelid swelling, as did our patient. None of the patients had hand dermatitis. A gardener could relieve his symptoms simply by avoiding direct

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Fig 1. Coleon 0.

American Journal of Contact Dermatitis, Vol8, No 1 (March). 1997: PP 8-9

CONTACT DERMATITIS FROM COLEUS 9

Fig 2. Coleus blumei, common hybrids.

contact with the coleus plants although they still were around him.4 He reacted to crushed leaves of several types of the Coleus blumei species, whereas 25 controls did not. A botanist doing a thesis on coleus reacted to a purified extract of the plants, Coleon 0, but not to the plant itself.5 A housewife reacted to the leaf of a coleus plant as well as to Coleon O.‘j The latter, a diterpene found in all coleus plants, has been shown to be a strong allergen7 with a potential for active sensitization.‘j The plants, nevertheless, only rarely seem to cause contact dermatitis despite their omnipresence and may require a special predisposition or moderate to severe exposition, though not necessarily occupational.

REFERENCES I. Love11 CR: Allergic contact dermatitis due to plants,

in Plants and the Skin. Oxford, Blackwell Scientific Publications,

1993, p 197 2. Fregert S: Manual of Contact Dermatitis. Copenha-

gen, Munksgaard, 1996 3. Weber LF: External causes ofdermatitis. Arch Derma-

to1 Syphil35:129-179, 1937 4. Saihan FM, Harman RR: Coleus sensitivity in a

gardener. Contact Dermatitis 4:234-235, 1978

5. Dooms Goossens A, Borghijs A, Degreef H, et al: Airborne contact dermatitis to Coleus. Contact Dermatitis

17:109-110,1987 6. van Hecke E, Hindryckx P, Geuns JM, et al: Airborne

contact dermatitis from coleus in a housewife. Contact Dermati- tis25:128-129,199l

7. Hausen BM, Devriese EG, Geuns JMC: Sensitising

potency of coleon 0 in Coleus species. Contact Dermatitis

19:217-218, 1988