Bullous irritant contact dermatitis caused by an alcoholic extract from Juglans regia leaves

Abstract

A 45-year-old non-atopic woman developed pigmented, bullous dermatitis, resembling a partial thickness burn, on her left knee ( Figure 1). She had wrapped walnut (J. regia) leaves soaked in grappa around her left knee for two consecutive nights in order to treat her painful, swollen knee. This "traditional" remedy had been suggested by a friend of hers who had found the information on the internet. Patch tests with the Italian Society of Allergological, Occupational and Environmental Dermatology (SIDAPA) baseline series (Lofarma, Milano, Italy) and with a piece of leaf "as is" were performed. Patch test chambers (Van der Bend, Brielle, The Netherlands) were applied in occlusion on the patient's back for 2 days. Readings were performed on day (D) 2 and D3 according to ESCD guidelines. The patient did not show any positive reactions. Bullous irritant contact dermatitis was diagnosed. DISCUSSIONJ. regia is a common large walnut tree whose parts are used to treat various diseases (eg, diarrhoea, sinusitis, arthritis, skin disorders, and diabetes) in popular medicine. In particular, fresh leaves of J. regia are applied on the forehead and body to alleviate fever, and on the joints to reduce rheumatic pain. 2 Cases of irritant contact dermatitis caused by the juice of green walnut husks have been described. 3,4 The responsible agent is juglone, an aromatic naphthoquinone present in J. regia husks and leaves. Juglone has an exogenous pigmenting action; for this reason, walnut husks are used in the preparation of vegetable hair dyes, similar to henna (Lawsonia inermis). 3 Although juglone is a strong sensitizer in guinea-pigs, few cases of allergic contact dermatitis caused by walnut husks have been described in humans. 3 In 2015,Foti et al described a case of allergic contact dermatitis caused by an unknown allergen contained in walnut husks. 5

Complicated atopic dermatitis in a healthy infant: Homemade walnut cream

“…It might also benefit patients with atopic dermatitis, either orally or as a topical medication, to reduce inflammation and improve skin hydration. 7,8 Along with this growth in the use of walnut as CAM, however, there is concern over its adverse effects, such as allergic reactions, contact dermatitis, digestive issues, and interactions with medications, and few studies reported notable side effects after applying walnut products. [7][8][9] Topical use of walnut leaves by a 45-year-old woman to alleviate the pain and inflammation of the knee resulted in contact dermatitis.…”

“…7,8 Along with this growth in the use of walnut as CAM, however, there is concern over its adverse effects, such as allergic reactions, contact dermatitis, digestive issues, and interactions with medications, and few studies reported notable side effects after applying walnut products. [7][8][9] Topical use of walnut leaves by a 45-year-old woman to alleviate the pain and inflammation of the knee resulted in contact dermatitis. 8 In addition, Neri et al 10 reported a couple of 4-and 5-year-old boys who developed skin-pigmented lesions and contact dermatitis on their buttocks after playing with fresh green walnut husks in the garden of their nursery school.…”

“…[7][8][9] Topical use of walnut leaves by a 45-year-old woman to alleviate the pain and inflammation of the knee resulted in contact dermatitis. 8 In addition, Neri et al 10 reported a couple of 4-and 5-year-old boys who developed skin-pigmented lesions and contact dermatitis on their buttocks after playing with fresh green walnut husks in the garden of their nursery school.…”

“…The walnut husks have an active ingredient called juglone, which improves fever, rheumatic pain, joint swelling, digestive problems, and skin disorders. It might also benefit patients with atopic dermatitis, either orally or as a topical medication, to reduce inflammation and improve skin hydration 7,8 …”

“…Topical use of walnut leaves by a 45‐year‐old woman to alleviate the pain and inflammation of the knee resulted in contact dermatitis 8 . In addition, Neri et al 10 .…”