Corns and Callus

People can get confused on whether they have a corn or a callus. This is an essay I wrote while studying to be a Foot Health Care Practitioner which may help you decide.

Corns

Module 6 portfolio task: Discuss the differences between diffuse callus and corns, highlighting the variances in the management of these two conditions.

Callus

Further reading:

Corns and calluses - NHS (www.nhs.uk)

Images used are from here.

The Royal College of Podiatry (rcpod.org.uk)

If you have a corn or callus it is advised that you seek the help of a professional (either a Foot Health Care Practitioner or a Podiatrist) who can explore with you why you may have one, what can be done to ease discomfort and any further treatments that may be necessary.

It is always a good idea to check your feet daily for any changes and to moisturise to keep skin soft . Emollients should not be used between the toes as skin can become macerated and cause further problems.

There are many different layers to the skin which can be affected by mechanical stresses from faulty footwear, deformities of the feet and high levels of activity (Freeman 2002). This causes a thickening of the stratum corneum (hyperkeratosis) due to hypertrophy or hyperplasia of the keratinocytes or corneocytes which can lead to either callus or corns (Garcia and Soler 2018). The differences and management of these are discussed below.

Burrow et al (2020, p41) suggest that calluses present as ‘a yellowish plaque of hard skin’ and occurs at sites stressed (as above) or by micro traumas. The margins of the hyperkeratotic lesion are likely to be undefined and of an even thickness (Freeman 2002). Diffuse-shearing calluses differ from discrete-nucleated as they have no central keratin plug and are not therefore likely to be mistook for warts (Panesar 2014). Treatment plans for this condition must be differentiated for individual and their circumstances, but scalpel debridement is considered for the initial treatment, along with footwear advice (Burrow et al 2020). Physical changes in the skin with the elderly may compound issues and make the foot less resilient (O’Keeffe 2022) – the use of humectants and moisturising preparations can therefore be part of the management of this condition (Ratcliffe 2022).

Corns have a central, inverted cone shaped core that can cause pain and inflammation and are divided into two subtypes - hard and soft (Freeman 2002). Hard corns are known as heloma durum, and are the most common type, usually found on the ‘dorsolateral aspect of the fifth toe or the dorsum of the interphalangeal joints of the lesser toes’ and look as though they have a polished surface (Panesar 2014). They can also occur beneath nails (subungal heloma) or become vascularised - heloma vasculare or neurovascular - heloma neurovasculare (Panesar 2014). If these lesions are left there is an increased risk of ulceration to those with neurological impairment, so treatment and management of these is necessary (Burrows et al 2020). There are a number of treatments available, including scalpel debridement, topical preparations such as caustics, gels and pads, plus electrodessication, ultrasound and low-level laser therapy (Burrows et al 2020). These should be considered so that pain is reduced, and that mobility and independent living can continue (O’Keeffe 2022).

Soft corns are known as heloma mole and commonly develop between the fourth and fifth toes (Freeman 2002). These are painful, macerated appearing lesions which develop due to extreme amounts of moisture (sweat) being absorbed and can lead to bacterial or fungal infections (Panesar 2014). The management of these is similar to hard corns as discussed above. If possible, basic foot hygiene should also be discussed as part of any management of the conditions.

Yarrarapu and Aboud (2022) suggest that there may be a third type of corn called a seed corn, which appears in non-weight bearing areas of the sole of the foot. Treatment is the same as other corns.

Corns and calluses therefore have similar aetiologies but have distinct differences in their presentations and managements. Several scalpel techniques are available, along with patient education by the health care professional, topical preparations and ultimately surgery if deemed necessary.

References

BURROW, G., ROME, K., AND PADHIAR, N., 2020. Neale’s Disorders of the Foot and Ankle, ninth edition, London.

FREEMAN, D. 2002. Corns and Calluses resulting from mechanical hyperkeratosis [online] [viewed 28/2/23] Available from https://www.aafp.org/pubs/afp/issues/2002/0601/p2277.html

GARCIA, C. AND SOLER, F., 2018. The effect of plantar hyperkeratosis debridement on self-perception of pain levels in older people. [online] [viewed 28/2/23] Available from https://www.sciencedirect.com/science/article/pii/S1873959818300723

O’KEEFFE, T. 2022. Aging – Theories and fall-out, The journal of Podiatric medicine. Summer 2022, Vol.87.No2, pp38-42.

PANESAR, K. 2014. Corns and Calluses: Overview of Common Keratotic Lesions [online] [viewed 28/2/23] Available from https://www.uspharmacist.com/article/corns-and-calluses-overview-of-common-keratotic-lesions

RATCLIFFE, M. 2022.The role of humectants in moisturising preparations. The journal of Podiatric medicine. Summer 2022, Vol.87.No2, pp28-32.

YARRARAPU, S., AND ABOUD, A. 2022. Corns [online] [viewed 28/2/23] Available from https://www.ncbi.nlm.nih.gov/books/NBK470374/