“Writer’s bump” is a condition which callouses formed on the lateral knuckle of the third finger in individuals who tightly gripped pens or pencils. Similarly, thumb callouses have been reported to develop due to excessive video game playing. A recent case series reported that scaly, thickened, mildly erythematous, poorly defined callouses were observed in 35 heavy cell phone users who held their cell phones more than 3 hours per day. The callouses were formed by the accumulation of keratinocytes in stratum corneum in response to excess pressure or friction. Keratolytic creams are suggested to counter the condition. Nonetheless, putting the cell phone down is obviously a better option.

Keywords: Writer’s bump, callous, cell phone

Reference

Lindgren et al. Case Rep Dermatol. 2019; 12(1):1-4.