PV occurs most often in young and healthy people, predominantly affecting the seborrheic areas of the trunk. It is favored by basal conditions of hyperhidrosis, seborrhea, tropical climates and habitual dressing with synthetic or occlusive undergarments. Clinically, in its usual form, it presents with multiple thin, irregular, isolated and/or confluent rounded scaly lesions with varying colors from patient to patient, ranging from hypopigmented to different hues of tan, light brown or pink. In typical cases the trunk is mainly affected, although involvement of unusual locations has been reported, including the scalp [1,2,3], eyelids [4,5], face [6] –although it is a common localization in children [7]-, axillae and groins [8,9], pubis [9], perineum [10], perianal, buttocks [11], popliteal [8,9] and antecubital fossae [2,9], web space [12], legs and arms [8], forearms [12], palms [13], nipple and areola [11,14,15], vulva [16], shaft of the penis [11,12,17,18,19], and glans [8,20,21]. It is not clear if there are specific predisposing or etiologic factors acting in the development of PV in those unusual locations [8]. Moreover, not always this nonclassical distribution of lesions occurs in conjunction with the typical eruption of PV, sometimes appearing as an isolated manifestation of it [8].

 Some infrequent and quite different clinical presentations have also been described, including a follicular form [22,23], inverse [10] –also called tinea inversicolor [24]- and many others, such as erythematous or rubra [11], atrophic [11,25] –induced by topical corticosteroid application [26], as an idiosyncratic response to Malassezia [27] or a delayed type of hypersensitivity reaction to its epicutaneous antigens [28]-, erythrasmoid [29,30], rotundiform [31], hyperkeratotic [32,33], confetti-like [34] and annular variants [35]; in one report, both hyperpigmented and hypopigmented lesions were detected, with different response to therapy [36].

In large series of patients we have not found mentions of this variety, presenting as a large single patch, not either in extensive reviews of PV [21]. However, as single reports, we have encountered eight well documented examples in the English and Spanish literature, with isolated solitary lesions exclusively affecting the areolar and periareolar area [14], medial thighs [35], popliteal fossae [37], interdigital space, penile shaft [12], antecubital fossae [12], submammary region [38], and neck [39].

Although it is not uncommon in daily practice to observe large lesions of PV formed by the confluence of individual polycyclic patches, they usually retain small areas of intermingled and unaffected skin [38], or satellital rounded lesions in close proximity, a fact that did not occur in our patients, devoid of other lesions.  

A rather different condition is perhaps that of rotundiform PV, in which a small, perfectly rounded, hypopigmented, scaly lesion appears as an early first episode of PV, analogous to the herald patch of pityriasis rosea [31]. We ignore the origin of this unique, unilateral and solitary presentation, similarly affecting the neck in the three cases, and neither what caused the reappearance of the same lesion in the same place a year after in our second case (although recurrent episodes of PV are common). We can only mention that it would be important to keep in mind the possibility of solitary PV in the presence of a tenuous, erythematous or hypopigmented, desquamative patch, albeit solitary.