Pitted Keratolysis

What is Pitted Keratolysis?

Pitted keratolysis is a bacterial infection that typically affects the outermost layer of the skin surface, specifically the thicker skin areas of the soles of the feet. The condition is characterised by pits in the skin surface and a very unpleasant smell. Effective treatment can clear pitted keratolysis within a month.

Can I get treatment online?

The Online Clinic can prescribe medications to treat pitted keratolysis online. Please complete the consultation form to begin.

Who gets Pitted Keratolysis?

Pitted keratolysis occurs worldwide. Both children and adults can be affected, although it is most common up to the age of 40 years. The condition is usually found in more males than females.

What causes Pitted Keratolysis?

Pitted keratolysis is caused by Gram-positive bacteria, including Corynebacterium species, Dermatophilus congolensis, and Kytococcus sedentarius. These bacteria produce enzymes (chemicals) that digest the skin protein keratin, thereby creating pits in the skin and producing sulphur compounds that cause the unpleasant smell.

Who is at risk of Pitted Keratolysis?

Factors increasing the risk of pitted keratolysis include:

• A condition called [hyperhidrosis – create link to our hyperhidrosis page] (excessive sweating)
• Prolonged use of occlusive footwear
• Poor foot hygiene
• A humid climate
• Physical activity
• Obesity
• Diabetes
• Immunodeficiency.

Prolonged moist conditions and/or poor foot hygiene may increase susceptibility to pitted keratolysis. Because the risk factors include conditions that cause the feet to sweat, this condition can affect people who practice good personal foot hygiene.

What are the signs and symptoms of Pitted Keratolysis?

Pitted keratolysis appears as distinct, shallow pits in the soles of the feet. The pits are skin-coloured, measure 1–7 mm, and may join together to form irregular areas of variable size. The pressure-bearing areas of the feet (e.g., toes, ball of the foot, and heels) are typically affected.

Symptoms include a very bad smell, moist feet, and foot pain and burning; rarely, the feet itch. However, pitted keratolysis can present without symptoms.

How is Pitted Keratolysis diagnosed?

Pitted keratolysis is usually diagnosed by a skin examination due to its distinct appearance. The condition is distinguished from hyperhidrosis due to the lack of skin pitting. It can be mis-diagnosed as other skin conditions, such as verrucae, tinea pedis, and basal cell naevus syndrome.

How is Pitted Keratolysis treated?

Treatment of pitted keratolysis involves targeting the bacterial infection by using topical antibiotics, including clindamycin, erythromycin, gentamycin, fusidic acid, and muciprocin. Alongside antibiotic use, treatment of pitted keratolysis also involves good foot hygiene and preventing moisture-promoting conditions.

Treatment can result in both the skin lesions and the smell resolving within 4 weeks. Pitted keratolysis does not usually recur, but this may be because those previously affected are aware of and avoid the factors leading to the condition.

How can a person with Pitted Keratolysis help themselves?

The following tips can help prevent the condition from occurring or recurring:

• Being aware of the risk factors and avoiding them
• Wearing clean breathable footwear including cotton socks
• Maintaining good personal foot hygiene
• Washing and drying feet thoroughly each day
• Not sharing footwear or towels with other people.

References

Maxwell J, Lam JM. Multiple malodorous pitted craters over the feet: Pitted keratolysis. Paediatr Child Health. 2021;26(7):390-391. doi: 10.1093/pch/pxab052.

de Almeida HL Jr, Siqueira RN, Meireles Rda S, Rampon G, de Castro LA, Silva RM. Pitted keratolysis. An Bras Dermatol. 2016;91(1):106-8. doi: 10.1590/abd1806-4841.20164096.

Saravanan R, Baalann KP. Pitted keratolysis. Pan Afr Med J. 2022;41:289. doi: 10.11604/pamj.2022.41.289.26065.

Kaptanoglu AF, Yuksel O, Ozyurt S. Plantar pitted keratolysis: a study from non-risk groups. Dermatol Reports. 2012;4(1):e4. doi: 10.4081/dr.2012.e4.

Takama H, Tamada Y, Yano K, Nitta Y, Ikeya T. Pitted keratolysis: clinical manifestations in 53 cases. Br J Dermatol. 1997;137(2):282-5. doi: 10.1046/j.1365-2133.1997.18211899.x.