clinical on the upper limbs Case studies Diogo Pereira Patricia Machado Paulo Morais Two gardeners, a male, 37 years of age Question 3 (patient 1) and his brother, 33 years of age How can we make the correct diagnosis of this (patient 2), presented with a 1-day history of ? slightly painful, unusual streaks and linear erythematous vesiculobullous plaques, with localised oedema, located on their forearms Question 4 (Figures 1A and 1B). On the previous day, What differential diagnoses would you consider? with blue skies and sunshine, they had been picking . Question 5 A healthy male bartender, 19 years of age What therapeutic measures would you (patient 3), who was preparing margaritas recommend? at a beach bar, presented with an erythematous vesicular rash, associated with Answer 1 burning sensation, on his right ante-cubital The diagnosis in all these presentations is fossa (Figure 1C). (PPD), a common cutaneous A previously healthy woman, 39 years of age phototoxic inflammatory eruption resulting from (patient 4), presented with erythematous and contact with plant-derived photosensitising mildly hyper-pigmented lesions in a bizarre compounds, generally furocoumarins (), pattern on her forearms (Figure 1D). A week followed by exposure to sunlight (especially before, she had been preparing juice for A 320–380 nm).1,2 her children at a table next to their outdoor swimming pool. On the following days she Answer 2 developed pain, oedema and tense bullae PPD is caused by at least four different plant in that location, with little improvement following application of cream containing families: (formerly Umbelliferae), 1–3 menthol and steroid. , Moraceae and Leguminosae. The Apiaceae family, the most common plant family implicated, has a distinctive floral umbel Question 1 that makes them easy to recognise.3 , What is the most likely diagnosis in these parsnips, and carrots are examples patients? from this group. The Rutaceae family includes and Ruta species and is the second most Question 2 common cause. The fig tree from the Moraceae What are the most common culprits for this family and the Psoralea corylifolia from the dermatosis? Leguminosae family are also implicated in

A B C D

Figure 1. Clinical appearance of the patients

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PPD.3 In our study, the culprit plants were the Table 1. Conditions to consider in the differential diagnosis of parsnips in patients 1 and 2 and lime in patients phytophotodermatitis1,2,4 3 and 4. Disease Clues for diagnosis Answer 3 Thermal burns Contact with hot substances Irritant contact Contact with strong irritants such as acid, alkali, solvent, Phytophotodermatitis is a clinical diagnosis. and others Therefore, a thorough history is essential in Drug induced bullous Recent exposure to systemic drugs making the diagnosis of PPD. The clinician disorders must ask about contact with fruits, plants and Allergic contact Contact with topical medications or other suspicious medicines or perfumes containing oils from dermatitis allergens botanical origin. It should be noted, however, Jellyfish stings, arthropod History of outdoor and nature-based activities, including that psoralens may also be transferred indirectly bites in the sea and forest through person-to-person contact.4 The Cutaneous larva migrans History of lying or walking barefoot on soil or tropical patient should also be asked about hobbies, beaches recreational activities, occupation and the Presence of local inflammatory signs and systemic symptoms use of ‘folk’ remedies.1,2,5 The patient usually Bullous Mainly affects infants and children, especially on the complains of a painful or burning sensation face and extremities; crusted, honey-coloured exudate rather than pruritus, which is commonly over erosions can be observed 2 associated with allergic . cutanea tarda Previous history of disease, hypersensitivity to On physical examination, and the sun and a recurrent rash on the exposed areas, oedema with or without blistering can be including , erosions, scarring, , observed in the acute phase, beginning in and milia. the first 24 hours after exposure, maximal at 48–72 hours, and lasting 3–5 days.2 The Answer 5 Provenance and peer review: Not commissioned; skin lesions often have a bizarre and linear Appropriate treatment for this condition includes:1,2 externally peer reviewed. configuration. The most commonly involved • avoidance of the offending agent References areas include the dorsa of the hands, wrists, • cool wet compresses during the acute phase 1. Cather JC, Macknet MR, Menter MA. Hyperpigmented forearms and lower legs.1 Hyperpigmentation • potent topical glucocorticoids in severe and macules and streaks. Proc (Bayl Univ Med Cent) 2000;13:405–06. appears 1–2 weeks after the exposure and may oedematous lesions 2. Baugh WP. Phytophotodermatitis. Available at: http:// last months to years.1,3 Sometimes the initial • oral salicylates or indomethacin for pain relief emedicine.medscape.com/ article/1119566–overview [Accessed at 15 April 2013]. inflammatory reaction may be subtle and only in adult patients 3. Bolognia J, Jorizzo J, Schaffer J. . In: the hyperpigmentation is evident.5 • skin-lightening cream if chronic Dermatoses Due to Plants. Elsevier; 2012. p. 273–89. hyperpigmentation results. 4. De Almeida HL Jr, Jorge VM. The many faces of phyto- Answer 4 . Dermatol Online J 2006;12:8. However, prevention is the best treatment for 5. Morais P, Mota A, Cunha AP, Peralta L, Azevedo F. Conditions to be considered in the differential PPD. Known furocoumarin-containing plants Phytophotodermatitis due to homemade oint- diagnosis of PPD are listed in Table 1.1,2,4 A should be avoided and not be planted near ment for Pediculosis capitis. Contact Dermatitis 2008;59:373–74. careful history and physical examination are play areas. It is prudent to advise the use of 6. Barradell R, Addo A, McDonagh AJ, Cork MJ, Wales usually enough to differentiate most of the , gloves and protective clothing while JK. Phytophotodermatitis mimicking child abuse. Eur J conditions. However, if necessary, laboratory in contact with these plants, especially on sunny Pediatr 1993;152:291–92. studies such as levels (to rule out days. If the contact occurs, prompt washing with porphyria cutanea tarda), photopatch tests soap and water is essential. (to distinguish between photoallergic and Authors phototoxic dermatitis), microbiological analysis Diogo Pereira MD, is a Family Medicine Trainee, of bullae aspirate, biopsy for histologic UCSP Gafanha da Nazaré, Aveiro, Portugal. examination, and further studies may be [email protected] 2 conducted. PPD occurring on a child may be Patricia Machado MD, is a Family Medicine mistaken for child abuse, as children may Trainee, USF Viriato, Viseu, Portugal acquire lesions from contact with other people Paulo Morais MD, is a dermatologist, Department who have juice on their hands; lesions may have of Dermatovenereology, Centro Hospitalar a bruise-like appearance usually in the shape of Tondela-Viseu, Portugal handprints or fingerprints.1,3,4,6 Competing interests: None.

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