Do you have experience washing socks? When faced with smelly socks that have been taken off, on the one hand, we feel disgust that makes us not want to touch them. On the other hand, we hope to wash them clean to avoid the breeding of bacteria and contamination of athlete's foot and onychomycosis. What you need to know is that fungal infections such as athlete's foot and onychomycosis are very common. Shoes and socks can easily harbor fungi, which can then be transmitted to others, or they may come back after treatment. So, here comes the question, when washing socks, should you turn them over and wash them? This question is small, but it is actually a scientific question.
A study: washing inside out vs not turning inside out
Some scholars from Japan conducted an interesting clinical study a few years ago, and the results were unexpected.
They selected a patient with athlete's foot as the subject of observation. The experiment required patients to wear socks for eight hours a day, and doctors then used a "blot culture" method to test the fungal load on the inside and outside of the socks.
It was found that on the inside of the socks (the side closest to the soles of the feet), all cleaning methods, whether washed with soap or cold water, front-side or inside out, were effective in removing most of the fungus on that side.
This means that the chemical action (detergent) and mechanical action (friction and water flushing) during the washing process are enough to penetrate the fabric and clean out the contaminants inside.
Interestingly, the results for the outside of the sock (the side that contacts the inside of the shoe) were surprising. They found that during cold water washing, if the socks were turned inside out, the amount of fungi detected on the outside of the socks was higher than when the socks were washed without turning them inside out.
The specific data is as follows: The initial number of fungal colonies on the inside of the socks worn by this patient was as high as 189.8. After turning over and cleaning, the number of fungal colonies on the outside increased from 0 to 2.1.
Based on this, they believe that washing socks inside out is not good (especially when washing socks in cold water). This conclusion is simply good news for lazy people...
As for the reason, they speculated that during the process of turning the socks, the high concentration of fungi and contaminated dander originally concentrated on the inside would be mechanically spread to the originally cleaner outside.
It's great news that you don't have to turn your socks inside out when washing them, and it saves you a lot of trouble. However, washing a pair of socks is not an easy task, and you still need to pay attention to other details.
Teach you step by step how to wash socks
If there is no fungal infection, the burden of washing socks will be smaller. The main thing is routine cleaning, followed by prevention-cutting off the spread of fungi and reducing the chance of fungal attachment.
If you have fungal infections such as athlete's foot or onychomycosis, you have to pay more attention to details and the requirements will be stricter. Basic advice is to change socks every day. This is mainly to eliminate the fungus's "reservoir" sweat and dander. These organic materials will provide an ideal source of nutrients for the growth of the fungus.
If you have time, it is recommended to wash the socks that you have replaced on the same day. This will cut off the nutritional source of the fungus mentioned above in time and prevent the fungus from multiplying in the socks. The longer dirty socks are left, the more established the fungus may become in colonizing the fibers.
The table below summarizes the differences between these two groups of people in handling socks.
Table 1. How different groups of people handle socks
Based on this table, we would like to add some information:
· Socks suspected of containing fungus should be stored separately from other clothing as fungus can be transferred in textiles;
· Mechanical actions such as repeated friction, kneading, rinsing/dehydration during sock washing are important factors in removing fungi and cannot be ignored;
· Water temperature of 30℃ can remove Candida, and 60℃ can kill Trichophyton rubrum (the most common pathogenic fungus of athlete’s foot);
· It is not necessary to use chemical disinfectants such as bleach and quaternary ammonium salts, but soaking socks has the icing on the cake effect;
· It is especially not recommended to let socks "dry" indoors. Airing or drying can effectively kill fungi.
How to clean personal items other than socks?
After talking about socks, other personal items should also be mentioned. This is because footwear, towels, bedding, and personal care tools are also reservoirs for fungi and their spores. Data show that the recurrence rate of skin fungal infections after cure is as high as 10% to 53%. One of the root causes of recurrence and refractory treatment lies in these personal products. Some fungal spores can survive for months or even years.
Below, we will discuss it. (PS: If you are not troubled by fungi, you can ignore this part.)
1 footwear
Shoes, other than socks, are the items that most directly come into contact with the affected area. They are warm, moist and accumulate a large amount of organic dander, providing ideal conditions for fungal growth. Studies have found that about 40% of patients with athlete's foot/onychomycosis can find fungi in their shoes.
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If the shoes are washable and can even come into contact with hot and boiling water, wash them first. As long as the shoes can withstand it, the higher the water temperature, the better.
If the shoes are inconvenient to be washed, if possible, you can use ozone disinfection or ultraviolet disinfection, which is at least more effective than using no other methods. For example, experiments have found that after multiple cycles of ultraviolet irradiation, the fungal load can be reduced by 76% to 85% (stack a buff: ultraviolet penetration is limited and can only act on the surface).
2 Home Textiles
Also be aware of household textiles such as towels, bedding and outerwear, which can also indirectly spread fungi.
Bedding and towels of patients with fungal infections should be stored and washed separately from family belongings. When washing, the surfactants in the detergent help to shed dirt and dandruff. Additionally, repeated rinsing and dehydration during the wash process are key distinguishing factors in removing fungi. It is recommended not to choose the fast washing mode as much as possible because the mechanical elution effect is not enough and the risk of fungal residues will be greater.
For heat-resistant mixed fibers, you can use a high-temperature steam iron for ironing. "Scalding" fungi is another effective physical sterilization method.
3 personal care tools
Manicure tools, grooming utensils, hairdressing tools and brushes can occasionally cause microscopic damage to the skin and, if contaminated with fungi, may lead to direct inoculation of the fungus into the skin.
It is recommended that these personal items should only be used by designated persons and should not be shared with family members, and the skin should be protected to avoid skin damage. After use, it can be washed with hot water or wiped and disinfected with medical alcohol.
In addition to the items mentioned above, you may also be concerned about how to treat the surfaces in public areas, such as what to do with the bathroom floor?
It’s easy to handle. One is "hard cleaning", which means careful cleaning and mechanical cleaning with tools to remove hair, dander, dust, and all kinds of visible dirt on the ground. Then, wipe the floor with household bleach (sodium hypochlorite) diluted 1:10. It can kill almost 100% of the fungi after 10 minutes. In addition, bathroom mats are areas where fungi are highly concentrated. It is recommended to replace them regularly or wash them with high-temperature water, and choose materials that are easy to clean.
Finally, combined with academic recommendations, we present comprehensive cleaning suggestions for personal items in the form of pictures:
Figure 1. Summary table of disinfection methods for household items, surfaces, and shoes and socks with fungal infections (it should be noted that the use of antifungal sprays such as terbinafine is not recommended because it may cause fungal resistance) (organized from reference materials)
In general, you don't have to worry too much about washing socks - it doesn't matter whether you turn them inside out or not, especially if you use hot water, detergent and enough mechanical cleaning, the socks can basically be washed clean. In addition, for "high-risk" people with athlete's foot or onychomycosis, the focus is not on turning over, but on daily isolation and thorough cleaning, such as separate storage, high-temperature washing, and adequate drying.
In addition, we also need to know that not only socks, but also items that are often in contact with feet, such as shoes, towels, and bedding, are also worth cleaning regularly to reduce the chance of fungi hiding.
References
[1] Watanabe K, Taniguchi H, Katoh T. Adhesion of dermatophytes to healthy feet and its simple treatment. Mycoses. 2000; 43(1-2): 45-50.
[2] Moriello K. Dermatophytosis: decontamination recommendations. August’s Consultations in Feline Internal Medicine. 2016; 7: 317-326.
[3] Akhoundi M, Nasrallah J, Marteau A, et al. Effect of household laundering, heat drying, and freezing on the survival of dermatophyte conidia. J Fungi (Basel). 2022; 8(5): 546.
[4] Gupta AK, Taylor D, Wang T, et al. Hygiene practices against dermatophytic fungi: A review of strategies to combat antifungal resistance. Biology (Basel). 2025; 14(8): 1016.
[5] Hammer TR, Mucha H, Hoefer D. Infection risk by dermatophytes during storage and after domestic laundry and their temperature-dependent inactivation. Mycopathologia. 2011; 171(1): 43-49.
[6] Tanaka K, Katoh T, Irimajiri J, et al. Preventive effects of various types of footwear and cleaning methods on dermatophyte adhesion. J Dermatol. 2006; 33(8): 528-536.
[7] Bloomfield S F, Exner M, Signorelli C, et al. The infection risks associated with clothing and household linesns in home and everyday life settings, and the role of laundry[C]//International Scientific forum on home hygiene. 2011.
[8] Gupta AK, Versteeg SG. The role of shoe and sock sanitization in the management of superficial fungal infections of the feet. J Am Podiatr Med Assoc. 2019; 109(2): 141-149.
Planning and production
Author丨Tang Jiaoqing, attending physician in dermatology, MD, member of China Popular Science Writers Association
Review丨Xu Min, deputy chief physician of the Department of Dermatology, Tianjin Medical University Metabolic Disease Hospital (Tianjin Medical University Zhu Xianyi Memorial Hospital)
Planning丨Zhang Yinuo
Editor丨Zhang Yinuo
Reviewer丨Xu Lai, Zhang Linlin