Confetti‐like hypopigmentation: a rare complication of common phototherapeutic modality

Abstract

Confetti-like hypopigmentation: a rare complication of common phototherapeutic modalityEditor Hypopigmentation and vitiligo occurring during psoralen and ultraviolet A (PUVA) therapy have been described in the literature. 1,2 Leucoderma punctatum, a confetti-like hypopigmentation, as a distinct entity was first described by Falabela et al. 3 A 21-year-old woman presented with multiple asymptomatic, punctiform, achromic spots of 1-month duration, distributed predominantly on extensor aspect of extremities. She had vitiligo vulgaris and was being treated with trimethylpsoralen 0.6 mg/kg, three times per week, followed by UVA exposure for 3 months before appearance of these lesions. Before starting PUVA treatment she was given 8 months' treatment of narrowband ultraviolet B (NBUVB), during which no similar lesion was observed. She was shifted to PUVA as there was minimal improvement of vitiligo with NBUVB. She had skin type V and had 40% repigmentation of the vitiliginous lesions over this period. Her disease was stable during therapy. On examination she had several small hypopigmented to depigmented macules, round to oval in shape, with well-defined margins and measuring about 1.5 mm, which were distributed over the repigmented areas ( fig. 1). These lesions were distributed over extensor aspect of the extremities and were predominantly perifollicular. There was no history of phototoxic reaction or inflammatory lesions. Skin biopsy was taken from a representative lesion, which showed patchy loss of pigment in basal keratinocytes with mild hyperkeratosis of the epidermis. The photochemotherapy was subsequently discontinued.Falabela et al. 3 first described leucoderma punctatum in 1988, in 13 vitiligo patients during and after PUVASOL (oral psoralen followed by solar UV exposure) treatment as leucoderma distinct from idiopathic guttate hypomelanosis and vitiligo. Later, Park et al. 4 reported four cases of generalized punctate leucoderma after UVB phototherapy for psoriasis. Most of the cases were females. Dogra et al. 5 first reported a case of leucoderma punctatum appearing after systemic PUVA therapy. Recently, it has been reported after topical PUVA treatment for segmental vitiligo by Park et al. 6 The typical skin lesions described are multiple discrete well-defined macules of size varying from 0.5 to 1.5 mm, most commonly located on the upper and lower extremities. Special stains for melanocytes show a decreased number of functional melanocytes. In ultrastructural study by Falabella et al., 3 cellular damage within keratinocytes and melanocytes was evident in form of intracellular oedema and intracytoplasmic vacuolar degeneration. Although pathogenesis is not well understood, the most likely cause is PUVA and UVB phototoxiciy-induced damage to melanocytes. Park et al. 4 also suggested that cumulative UVB phototoxicity may be the cause of leucoderma punctatum. In this case, perhaps the exposure to both NBUVB and PUVA was the cause of phototoxicity and appearance of these lesions. It is important to be aware o...

Idiopathic guttate hypomelanosis‐like lesions in patients with mycosis fungoides: a new adverse effect of phototherapy

“…The literature contains several case reports of various clinical forms of hypopigmentation appearing during PUVA 6–9,11–14 or, in one case, 10 NB‐UVB. Most of the patients had MF and a smaller number had psoriasis or vitiligo 6–14 . However, the literature specifically on IGH occurring during phototherapy is strikingly sparse.…”

“…Disorders of hypopigmentation, such as leucoderma, vitiligo and confetti‐like hypopigmentation, have occasionally been reported in association with phototherapy, mostly in patients with MF 6–14 . IGH‐like lesions appearing during phototherapy have been previously reported in only one patient being treated for MF 13 …”

Low-Fluence Q-Switched 1,064-nm Neodymium-Doped Yttrium Aluminum Garnet Laser for the Treatment of Facial Partial Unilateral Lentiginosis in Koreans

“…The mechanism behind hypopigmentation associated with low‐fluence 1,064‐nm QS Nd:YAG laser treatment is not clear, but a similar phenomenon, known as “leucoderma punctata,” has been described in vitiligo treated with topical or oral psoralen followed by ultraviolet (UV)A irradiation or solar ultraviolet light exposure and in psoriasis treated with UVB phototherapy . Histologic studies have revealed patchy loss of melanin pigment in basal keratinocytes and fewer functional melanocytes and melanin granules . The precise pathophysiology of leucoderma punctata has not been fully elucidated, but one widely accepted theory is that the cumulative phototoxic damage to melanocytes and keratinocytes from phototherapy causes it .…”

Annular hypopigmented mycosis fungoides: a novel ringed variant

“…Leukoderma punctatum represents a clinical condition presenting as confetti‐like hypopigmented macules described most commonly in women being treated with 8‐methoxypsoralen and sunlight as a UV source for vitiligo but also has been reported with light chamber UV‐A and topical PUVA 13–15 . Park et al reported four cases of generalized leukoderma punctatum after UV‐B phototherapy for psoriasis, while Bhatnagar et al reported a single case of a vitiligo patient who had both UV‐B and PUVA therapy that developed the leukoderma punctatum after the PUVA 16,17 . On histopathologic examination, patchy loss of melanin in the basal layer with decreased number of melanocytes was observed without any other remarkable change in the epidermis.…”