Viewpoints in dermatology • Correspondence
Correspondence
Psoralen ultraviolet A-induced melanonychia
(a)
doi: 10.1111/ced.12481 A 53-year-old white man presented with a 10-year history of psoriasis affecting the dorsa of both hands. There were no associated nail changes, and the patient’s feet were unaffected. His mother had psoriasis, which was being treated with methotrexate. He had failed to respond to topical treatments, including superpotent corticosteroids, combined potent corticosteroid with calcipotriol, and dithranol. Topical hand psoralen ultraviolet A (PUVA) photochemotherapy was commenced, but after 3 weeks of twice-weekly treatment, there was little benefit. Thus, the treatment was changed to oral 8-methoxypsoralen (8-MOP) PUVA. Twice-weekly treatments were given for 5 weeks (cumulative dose 61.5 J/cm2), but the patient was unable to tolerate treatment due to irritation and blister formation. At follow-up, the patient was found to have symmetrical longitudinal bands of nail pigmentation affecting all fingernails, but most prominently, his thumbs (Fig. 1a,b). The patient reported onset of these bands within the first week of starting oral PUVA treatment. A number of speckled lentigines were seen over sites of previous plaques of psoriasis on the patient’s fingers. New pigmentation was not seen at any other sites, and specifically, the toenails were spared. Laboratory investigations, including full blood count, urea and electrolytes, liver and thyroid function tests, bone profile, haematinics and glucose all gave normal results. Four months after treatment, the bands of melanonychia had completely resolved. The development of pigmentary changes on the skin during PUVA photochemotherapy is well documented, with lentigines being the most frequent change.1 Development of melanonychia is much rarer, with only occasional cases reported in the literature.2 The mechanism of melanonychia development is not clear. Perria found that it is the distal, rather than the proximal matrix of the nail that contains an active melanin synthesis compartment.3 It is suggested that on exposure to UVA, the melanocytes in this compartment are stimulated to increase melanin production, resulting in melanonychia.1 Some reports suggest that the UVA
ª 2015 British Association of Dermatologists
(b)
Figure 1 (a) Symmetrical bands of melanonychia on the
patient’s nails; (b) melanonychia was most prominent in the thumbnails.
dosage is the key factor, as PUVA-induced lentigines are seen after a cumulative dose of 440 J/cm2.4,5 In our case, the melanonychia occurred after a much lower cumulative dose (61.5 J/cm2), which is similar to other reports,1,4 although the dose varies, with incidences of 42–430 J/cm2 cumulative UVA doses reported.2 A more widely accepted theory is that the type of psoralen is of greater importance, with almost all reports of PUVAinduced melanonychia occurring in patients who were given 8-MOP.1,5 The course of the melanonychia is variable, but in most cases, it seems to resolve after treatment is discontinued.5 The melanin that has been transferred onto the
Clinical and Experimental Dermatology (2015) 40, pp331–338
331
Correspondence
nail plate slowly advances distally as the nail grows out. However, some reports do not state if the melanonychia persisted after treatment,4 and there are three cases of resolution occurring during treatment.1,5 PUVA-induced melanonychia is rare, but clinicians should be aware of the potential for it to arise. It appears to be a benign process, allowing reassurance to be offered to patients in whom it occurs. It is possible that PUVAinduced melanonychia is more common than the number of reports in the literature suggests.
(a)
G. J. Parkins, A. D. Burden and A. Makrygeorgou Alan Lyell Centre for Dermatology, Western Infirmary, Glasgow, UK E-mail: [email protected] Conflict of interest: the authors declare that they have no conflicts of interest. Accepted for publication 6 May 2014
References 1 Ledbetter LS, Hsu S. Melanonychia associated with PUVA therapy. J Am Acad Dermatol 2003; 48: S31–2. 2 Boyvat A, Yavuz C, Kocyigit P, et al. Melanonychia induced by PUVA therapy. J Eur Acad Dermatol Venereol 2004; 18(Suppl. 2): 243. 3 Perria C, Michiels JF, Pisani A, Ortonne JP. Anatomic distribution of melanocytes in normal nail unit: an immunohistochemical investigation. Am J Dermatopathol 1997; 19: 462–7. 4 Weiss E, Sayegh-Carreno R. PUVA-induced pigmented nails. Int J Dermatol 1989; 28: 188–9. 5 Kaptanoglu AF, Oskay T. Symmetrical melanonychia of the thumb-nails associated with PUVA in psoriasis. J Dermatol 2004; 31: 148–50.
Shiitake dermatitis with oral ulceration and pustules
(b)
Figure 1 (a) Flagellate erythema on the trunk; (b) oral apht-
hous-type ulceration.
doi: 10.1111/ced.12500 We present an unusual case of shiitake dermatitis. A 42-year-old man, who was usually fit and well, presented with a 4-day history of an eruption that had started 36 h after he had eaten stir-fried shiitake mushrooms. The eruption began in the groin and axilla, before becoming generalized. The rash was itchy and sore, and the patient also reported painful lesions in his mouth. He was otherwise systemically well and had taken no medications. He reported having had a similar rash in the past, also after eating mushrooms. Physical examination revealed linear, urticated, erythematous streaks on the patient’s back, neck and limbs (Fig. 1). Several pustules were also noted. There were multiple small ulcers in the mouth. The flagellate appearance of the rash was typical of shiitake dermatitis.
332
Clinical and Experimental Dermatology (2015) 40, pp331–338
Histological examination of a skin biopsy revealed, mild spongiosis with neutrophilic exocytosis and features of a neutrophilic dermatosis, in keeping with shiitake dermatitis (Fig. 2). Shiitake dermatitis was first described in the Japanese population, where these mushrooms are eaten more frequently. It was initially labelled as ‘toxicoderma’.1 There have now been multiple reports from around the world. The eruption is due to the compound lentinan within the mushrooms, which is broken down by heat, and therefore the reaction is more common after eating raw or lightly cooked (e.g. stir-fried) mushrooms.2 Lentinan is believed to have health benefits such as lowering blood pressure and cholesterol,3 and is used therapeutically in Japan, but has had skin reactions documented.4 Differentials for a flagellate rash include drug reactions (bleomycin, peplomycin or docetaxel) or connective tissue
ª 2015 British Association of Dermatologists
Correspondence
Psoralen ultraviolet A-induced melanonychia
(a)
doi: 10.1111/ced.12481 A 53-year-old white man presented with a 10-year history of psoriasis affecting the dorsa of both hands. There were no associated nail changes, and the patient’s feet were unaffected. His mother had psoriasis, which was being treated with methotrexate. He had failed to respond to topical treatments, including superpotent corticosteroids, combined potent corticosteroid with calcipotriol, and dithranol. Topical hand psoralen ultraviolet A (PUVA) photochemotherapy was commenced, but after 3 weeks of twice-weekly treatment, there was little benefit. Thus, the treatment was changed to oral 8-methoxypsoralen (8-MOP) PUVA. Twice-weekly treatments were given for 5 weeks (cumulative dose 61.5 J/cm2), but the patient was unable to tolerate treatment due to irritation and blister formation. At follow-up, the patient was found to have symmetrical longitudinal bands of nail pigmentation affecting all fingernails, but most prominently, his thumbs (Fig. 1a,b). The patient reported onset of these bands within the first week of starting oral PUVA treatment. A number of speckled lentigines were seen over sites of previous plaques of psoriasis on the patient’s fingers. New pigmentation was not seen at any other sites, and specifically, the toenails were spared. Laboratory investigations, including full blood count, urea and electrolytes, liver and thyroid function tests, bone profile, haematinics and glucose all gave normal results. Four months after treatment, the bands of melanonychia had completely resolved. The development of pigmentary changes on the skin during PUVA photochemotherapy is well documented, with lentigines being the most frequent change.1 Development of melanonychia is much rarer, with only occasional cases reported in the literature.2 The mechanism of melanonychia development is not clear. Perria found that it is the distal, rather than the proximal matrix of the nail that contains an active melanin synthesis compartment.3 It is suggested that on exposure to UVA, the melanocytes in this compartment are stimulated to increase melanin production, resulting in melanonychia.1 Some reports suggest that the UVA
ª 2015 British Association of Dermatologists
(b)
Figure 1 (a) Symmetrical bands of melanonychia on the
patient’s nails; (b) melanonychia was most prominent in the thumbnails.
dosage is the key factor, as PUVA-induced lentigines are seen after a cumulative dose of 440 J/cm2.4,5 In our case, the melanonychia occurred after a much lower cumulative dose (61.5 J/cm2), which is similar to other reports,1,4 although the dose varies, with incidences of 42–430 J/cm2 cumulative UVA doses reported.2 A more widely accepted theory is that the type of psoralen is of greater importance, with almost all reports of PUVAinduced melanonychia occurring in patients who were given 8-MOP.1,5 The course of the melanonychia is variable, but in most cases, it seems to resolve after treatment is discontinued.5 The melanin that has been transferred onto the
Clinical and Experimental Dermatology (2015) 40, pp331–338
331
Correspondence
nail plate slowly advances distally as the nail grows out. However, some reports do not state if the melanonychia persisted after treatment,4 and there are three cases of resolution occurring during treatment.1,5 PUVA-induced melanonychia is rare, but clinicians should be aware of the potential for it to arise. It appears to be a benign process, allowing reassurance to be offered to patients in whom it occurs. It is possible that PUVAinduced melanonychia is more common than the number of reports in the literature suggests.
(a)
G. J. Parkins, A. D. Burden and A. Makrygeorgou Alan Lyell Centre for Dermatology, Western Infirmary, Glasgow, UK E-mail: [email protected] Conflict of interest: the authors declare that they have no conflicts of interest. Accepted for publication 6 May 2014
References 1 Ledbetter LS, Hsu S. Melanonychia associated with PUVA therapy. J Am Acad Dermatol 2003; 48: S31–2. 2 Boyvat A, Yavuz C, Kocyigit P, et al. Melanonychia induced by PUVA therapy. J Eur Acad Dermatol Venereol 2004; 18(Suppl. 2): 243. 3 Perria C, Michiels JF, Pisani A, Ortonne JP. Anatomic distribution of melanocytes in normal nail unit: an immunohistochemical investigation. Am J Dermatopathol 1997; 19: 462–7. 4 Weiss E, Sayegh-Carreno R. PUVA-induced pigmented nails. Int J Dermatol 1989; 28: 188–9. 5 Kaptanoglu AF, Oskay T. Symmetrical melanonychia of the thumb-nails associated with PUVA in psoriasis. J Dermatol 2004; 31: 148–50.
Shiitake dermatitis with oral ulceration and pustules
(b)
Figure 1 (a) Flagellate erythema on the trunk; (b) oral apht-
hous-type ulceration.
doi: 10.1111/ced.12500 We present an unusual case of shiitake dermatitis. A 42-year-old man, who was usually fit and well, presented with a 4-day history of an eruption that had started 36 h after he had eaten stir-fried shiitake mushrooms. The eruption began in the groin and axilla, before becoming generalized. The rash was itchy and sore, and the patient also reported painful lesions in his mouth. He was otherwise systemically well and had taken no medications. He reported having had a similar rash in the past, also after eating mushrooms. Physical examination revealed linear, urticated, erythematous streaks on the patient’s back, neck and limbs (Fig. 1). Several pustules were also noted. There were multiple small ulcers in the mouth. The flagellate appearance of the rash was typical of shiitake dermatitis.
332
Clinical and Experimental Dermatology (2015) 40, pp331–338
Histological examination of a skin biopsy revealed, mild spongiosis with neutrophilic exocytosis and features of a neutrophilic dermatosis, in keeping with shiitake dermatitis (Fig. 2). Shiitake dermatitis was first described in the Japanese population, where these mushrooms are eaten more frequently. It was initially labelled as ‘toxicoderma’.1 There have now been multiple reports from around the world. The eruption is due to the compound lentinan within the mushrooms, which is broken down by heat, and therefore the reaction is more common after eating raw or lightly cooked (e.g. stir-fried) mushrooms.2 Lentinan is believed to have health benefits such as lowering blood pressure and cholesterol,3 and is used therapeutically in Japan, but has had skin reactions documented.4 Differentials for a flagellate rash include drug reactions (bleomycin, peplomycin or docetaxel) or connective tissue
ª 2015 British Association of Dermatologists
