Talar Callosity in Children—What, Who, Why?
Article Outline
The talar callosity is a relatively uncommon ankle lump in children.1, 2, 3 Although asymptomatic and entirely “benign,” it is a major cause of parental concern. Clinically, the talar callosity refers to an area of hyperkeratotic skin on the anterolateral aspect of the ankle. Talar callosities are typically 2.0 to 2.5 cm in diameter, may be unilateral or bilateral, and are usually a shade darker than the surrounding skin (Figure 1). They can be associated with smaller callosities over the ipsilateral lateral malleolus, fifth metatarsal base or head, or other bony prominence in the foot.
Figure 1
A talar callosity.
For 5 years, 26 children at our institution had talar callosities. There were 17 boys (65.4%) and 9 girls (34.6%) between 3 and 8 years of age (mean age, 5.3 years). All 26 children had generalized ligament laxity and a preference for cross-legged sitting without shoes. Sixteen children (61.5%) had bilateral callosities. The 10 children (38.5%) with unilateral involvement consistently sat cross-legged so that the ankle with the callosity (Figure 2) was the one drawn closer to the body and bore the additional weight of the contralateral thigh. It was also the side on which there was greater hindfoot equinovarus and forefoot adductus and supination, thrusting the anterolateral aspect of the talar head into prominence. This position of the foot in a cross-legged sitting position can be readily simulated with passive manipulation; in our experience, this simple demonstration greatly facilitates parents’ understanding of the condition. The families of 19 children were satisfied with simple reassurance on the basis of clinical evaluation. At the request of their parents, 4 children underwent radiography of the ankle and foot, and 3 children underwent ultrasound scanning; the results of all 7 investigations were normal.
Figure 2
The foot with the larger callosity is the one drawn closer to the body in cross-legged sitting.
In summary, the risk factors for the development of talar callosities in a child are age 3 to 8 years, generalized ligament laxity, and cross-legged sitting without footwear. This clinical entity is probably more common in Asian communities, where footwear is not worn indoors, than in Western communities. Once important differentials such as ganglion cysts and solid lesions are excluded, reassurance and advice on alternative sitting positions are all that is needed. Special investigations are not indicated. It is also worth reassuring parents that shoe straps are not the culprit.
References
PII: S0022-3476(10)00727-4
doi:10.1016/j.jpeds.2010.08.035
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