Painful Piezogenic Pedal Papules in a Female Babysitter

Abstract

To the Editor: Piezogenic pedal papules (PPPs) are featured by skin-colored hidden lesions and visible only on weight bearing or pressure application. PPP often presents on both heels. Here, we report a case of PPP, which only involved the right heel. A 40-year-old Chinese woman presented multiple painful papules for 2 years on her right heel. The pain was more pronounced after prolonged standing. Physical examination identified multiple, 0.5–1.0-cm sized, soft, relatively well-demarcated, and skin-colored papules on the medial aspect of her right heels (Fig. 1A). These papules were more prominent by pressing the heel side (Fig. 1B). Her medical and family history was not significant. She worked as a babysitter for years, was never overweight and denied any traumatic events related to the lesions. Histopathological examination revealed normal epidermis with several fat lobules surrounded by dense collagen fibers in deep dermis (Fig. 1C). Together with the clinical manifestation, she was diagnosed with PPP, and advised to use compression stockings and to avoid longtime standing.FIGURE 1.: Clinical and histological manifestations of piezogenic pedal papules. Yellowish papules and nodules on the right heel without (A) and with pressure (B). C, Several fat lobules in dermis (indicated by arrows, HE × 20). Inset image shows the adipose tissue surround by thick collagen fibers (Hematoxylin and eosin (H&E) × 200).The prevalence of pedal papules varied widely in literature: 2.4%, 62%, and 100%.1 The discrepancy may be attributed to the secretiveness of the disease. It appears in children and adults without apparent sexual bias. The pathogenesis of PPP is unclear. Most scholars believe it is a herniation of fat through the dermis. Repetitive stress, trauma, and connective tissue defect are the major factors contributing to the development of PPP because most of the published cases were athletes, obese subjects, or patients with Ehlers–Danlos syndrome. Our patient was a babysitter, a job requiring longtime standing and walking. In addition, she might have some habitual gesture that makes her right heel handle more stress of her body weight than her left heel, eventually resulting in the unilateral lesions. Piezogenic papules generally present as multiple, 0.2–1.0-cm sized, soft and skin-colored papules on heels, occasionally on wrists. Most patients with PPP were asymptomatic. Only 7.1% of PPP were painful, which is attributed to ischemia caused by the extrusion of vasculature and nerves associated with fat tissue.2 The typical histological findings of PPP are featured by thick dermis and large fatty lobules formed by the fusion of smaller fat chambers. The fusion could be due to the degeneration or the complete absence of thin fibrous septum in subcutaneous tissue. Ultrasonography may help in the diagnosis of PPP if the histological changes were atypical.3 The differential diagnosis includes cysts, verruca vulgaris, and lipoma. Asymptomatic patients do not require treatments. The benefits of early intervention with compression stockings for unpainful PPP are unclear. For painful PPP, managements include avoiding standing for long time, reducing foot trauma, weight loss, and using compression stockings and heel cups.1 Acupuncture, repeated injections of betamethasone, and bupivacaine were reported effective.4,5 Surgery is the last and rare choice. However, these therapies are often unsatisfactory.