Pedal Poppers: Soles to Hold.

Sir,

Piezogenic (Peizo – pressure, genic – giving rise to) pedal papules, usually present as skin colored painless bumps on the heel. These result from herniation of subcutaneous fat through connective tissue defects into the dermis. However, if painful, they can be distressing and difficult to treat.

A 20-year-old girl presented with painful lesions on both heels since 15 days. There was a history of aggravation of pain on walking or standing for long periods. Clinical examination revealed multiple skin-colored papules on the medial aspect of heels giving it a cobblestone appearance. The papules were approximately 8–10 in number on each heel, 3–8 mm in diameter, soft in consistency and became prominent on standing or applying pressure [Figure 1a] and disappeared on lifting the foot off ground and lying down [Figure 1b]. Skin biopsy from a papule suggested fragmentation of dermal elastic fibers with herniation of subcutaneous fat into the dermis [Figure 1c and d]. On the basis of clinical and histopathological findings, a diagnosis of painful piezogenic pedal papules was made. The possibility of any associated hereditary connective tissue disease was ruled out clinically. No orthopedic abnormality was found on imaging. The patient was counseled to avoid prolonged standing and was provided satisfactory symptomatic management with “Micro-Cellular Rubber (MCR) insoles with a heel raise” [Figure 2].

Figure 1

(a) Lesions become prominent on pressure (b) lesions disappear on lifting the foot off ground (c) fragmentation of elastic fibers (H and E, ×10) (d) herniation of subcutaneous fat in dermis (H and E, ×40)

Figure 2

Microcellular rubber insoles with a heel raise

Painless piezogenic pedal papules often go unnoticed as they are symptomless. They represent normal peripheral fat chambers of the heel. They become painful only when there is entrapment of fat and its neurovasculature resulting in ischemia and anoxia. Though most often idiopathic, common associations of this entity include obesity, flat feet, excessive weight bearing, trauma, and collagen defect disorders such as Ehler–Danlos syndrome.[1] Xanthomas, tophi, and infantile pedal papules comprise the frequent clinical differentials.[2]

Painful piezogenic pedal papules are a therapeutic hurdle for the dermatologist. Conservative treatment measures include weight loss, avoiding standing for long periods, and reducing foot trauma. Various case reports suggest the use of compression stockings,[3] foam-fitted plastic heel cups,[3] local electroacupuncture,[3] combination of a steroid and anesthetic injections,[4] low-level laser light therapy[1] and even surgical excision[5] with variable success. However, we were able to manage this recalcitrant condition both successfully and conservatively with “MCR insoles with a heel raise.” The therapeutic aim is to prevent the excessive trauma caused with a hard sole and to redistribute the weight to the anterior part of the foot by increasing the thickness of the insole over the heel area. This will prevent herniation and resultant entrapment of fat. MCR footwear and insoles can be looked upon as a cheap and effective therapeutic option for institutional management of painful piezogenic pedal papules.

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Conflicts of interest

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