cycling perineum lump cycling perineum lump

A saddle sore in humans is a skin ailment on the buttocks due to, or exacerbated by, horse riding or cycling on a bicycle saddle. Rodier JF, Janser JC, Rodier D. Induration nodulaire prinale. If you're older than 50 years old, then your prostate glands will shrink over time due to declining health. Pelvic pain may signal a problem with your urinary tract, A purpuric rash is made up of small, discolored spots under your skin from leaking blood vessels. Inside your body, your perineum consists of tissue that makes up the bottom of your pelvic cavity. Journal of lower genital tract disease, 18(4), e84-e89. It produces more fluid and swells thats when you get a painful, firm lump (of variable size) under the sitting bone. Hi. Folliculitis is an infection of tiny hair follicles in your perineum, which may occur when hair follicles are damaged by friction and seat pressure. 2003;27:9991007. Gentlemen, last chance. If the lesion is therapy resistant, some authors recommend local injection of corticosteroids or hyaluronidase. We report a case of a 59-year-old amateur cyclist male who presented with 2 bilateral nodular perineal lesions that were . The American journal of surgical pathology, 35(1), 110-114. It is characterized on imaging by a hypoechoic mass with cystic change and absence of . A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. They may also order a urine or blood test to check for any abnormalities that might be related to the perineum lump. Well start with common causes in all sexes, and then well get down to the specific causes of perineum lumps in people with vulvas and people with penises. So, I hope this helps anyone out by what I know as of right now. Perianal lesions are those that can be completely visualized without buttock traction within a 5 cm radius of the anal opening. Perineum pain from bicycling in men may indicate or lead to more serious reproductive and infectious conditions. I had a hysterectomy in August '12, and cancer came back a couple of months ago. We strive to create a comfortable environment for readers, with articles that are easy to read, informative, and helpful. One thing we can all agree on, is that they are an irritation in the groin area from riding a bicycle. You can rub some on the chamois itself as well as your . Biker nodule is believed to be a friction phenomenon between the ischium and outer aspect of a racing bicycle seat sitting high up in the perineum near the base of the penis pushing the superficial perineal fascia onto the ischium. Cysts and tumors are two common types of lumps. A general doctor is not a specialist. The pain may be worse during, or right after, a bowel movement. This will help keep the blood flowing and prevent pressure from building up in the area. What is infection of the perineum? 2003;42:61522. Men may reduce or avoid perineum pain by using a neutral or slightly upward seat tilt. The lesion has been previously known by many synonyms, including 'third or supernumerary testicle', 'accessory testicle', 'perineal hygroma or induration' [1-5].It is typically located in the paramedian region of the perineum, posterior to the scrotal sac, and is covered with normal skin. Abscesses are collections of pus that can form when an infection spreads beyond the perineum lump. Boston University School of Medicine Sexual Medicine: Erectile Dysfunction and Bicycling; Irwin Goldstein, M.D. Take pain medication like ibuprofen (Advil) to reduce swelling and pain. Been almost a year since I had the dreaded "lump", and it completely gone. Check your saddle height as well. (2015). To date, three cases have been reported in the English literature. Get answers to your common health questions about diseases and conditions like diabetes, ADHD, pregnancy, psoriasis, sex, arthritis, heart disease, cancer, and mental health from OnHealth.com. Changing your seat to a fluid-filled model may help prevent perineum pain by reducing the incidence of saddle sores. This will help to reduce swelling and pain. Although well known to sport medicine specialists, it is a scarcely documented entity in the pathology literature. The majority of riders will be happy with a flat saddle position, with the saddle rails set in a middling position fore/aft, but that's not always the case. We disclaim all responsibility for the professional qualifications and licensing of, and services provided by, any physician or other health providers posting on or otherwise referred to on this Site and/or any Third Party Site. Furuncles are increasingly painful as they continue growing. Special attention should also be given to the pants of the cyclist. You may notice them as tender or painful lumps close to your perineum. Imaging has an additional role in the differentiation between bikers nodule and other causes of a perineal swelling. It often develops in three stages: skin abrasion, folliculitis (which looks like a small, reddish acne), and finally abscess. A lump in the perineum (area between anus and vagina for woman) can be due to a number of causes. REFERENCE Welcome to RIDO cycling. The bikers nodule is a rarely appearing perineal nodular induration of the cyclist. Cyclist's nodule: no smooth ride. Finally, make sure you clean the area well after each bowel movement. perineum anatomy engraving 1886 - female perineum stock illustrations. This bacteria-filled pore originates as a raised pink/red tender spot on the butt, inner thigh, and/or groin and most commonly between your genitalia and anus. Having a perineal cyst or lump can be caused by anything from an injury to a sexually transmitted illness (STI). Biker's nodule"--perineal nodular induration of the cyclist. Bye for now. There is some variability in how the boundaries are defined. Histopathology shows a myxoid degeneration of the fatty tissue and collagen fibers overlying the ischial tuberosities, caused by necrosis of the superficial perineal fascia, sometimes with formation of pseudocysts [15]. Pelvic floor symptoms in female cyclists and possible remedies: a narrative review. This is especially important if theyre concerned that you may have an infection or cancerous tumor. Perineum lumps are usually benign, meaning theyre not cancerous. Cysts are fluid-filled sacs that can form anywhere on the body. Hi, About 2 weeks ago I noticed a large tender lump to the right of my perineum (between vagina and anus) its about the size of a grape. Perineal nodular swelling in a recreational cyclist Diagnosis The diagnosis of a biker's nodule was made, based merely on the clinical history, the typical location and the imaging findings. Specifically, I had a huge swelling on one side of my vulva that grew almost as soon as I started to . . "It would appear that the testis could become twisted between the thigh and the saddle as . Here are some other symptoms you may notice along with a perineum lump: See your doctor if you experience any intense pain or discomfort along with these symptoms. I was travelling to and from the hospital every day n sitting by his bed side for 8-9 hrs a dayfor 8 months , I'd stopped eating a small sandwich some days nothing other days . Was wondering whether mine is internal piles with no bleeding at all but can feel lump quite big mass about 1.5cm at perineum. McCluggage, W. G., & Smith, J. H. (2011). Bicycling shorts Avoid shorts with seam lines that overly the ischial tuberosity and perineum. However, they can fill with fluid over time and become large enough to make it difficult to sit. Coutant-Foulc, P., Lewis, F. M., Berville, S., Janssen, B., Guihard, P., Renaut, J. J., & Moyal-Barracco, M. (2014). Cancerous lumps are usually hard, painless and immovable. Privacy Policy The tissue for diagnosis can be procured in multiple different ways which include: Many clinical conditions may have similar signs and symptoms. The important thing is that you get into a specialist and find out what it is. Furuncles are generally more painful than folliculitis, and may initially look and feel like a pimple. I am started having cramping/pelvic pain the last month and noticed a li m a 30 year old male i do smoke recreationally. Checking the websites source, or if the article is from a peer-reviewed journal, can help ensure that you are getting accurate information. Went to consult an O&G doctor and she said its only tissue appearing at the perineum area. Person can feel it on touching and it hurts on wiping the area, sitting or moving around. The risk factors for Cyclist Nodule include the following: It is important to note that having a risk factor does not mean that one will get the condition. Never disregard the medical advice of your physician or health professional, or delay in seeking such advice, because of something you read on this Site. It develops in the soft tissues of the perineum immediately posterior to the scrotum, as a bilateral or single, central or lateralized mass. An examination will be needed to know the cause and treatmen. Representation Of The Anatomy Of The Female Genital Organs Gynecological View. When he eventually arrived home for me to become his 24/7 carer I started to eat more . Here are some treatments you can try to help reduce the discomfort, pain, or swelling that might accompany a perineum lump: Seek immediate medical help if you notice any of the following symptoms in addition to the perineum lump: Most of the time, a perineum lump is harmless if it doesnt come with any pain, swelling, or other unusual symptoms. Case Discussion. perineal area which occurred during cycling. Use antibiotic ointments such as Neosporin to aid healing. It's sensitive to the touch, but it's not much to write home about otherwise. I love to write and share science related Stuff Here on my Website. de Saint Aubain Somerhausen N, Geurde B, Couvreur Y. Perineal nodular induration: the third testicle of the cyclist, an under-recognized pseudotumour. Medical issues In addition, people often share articles and videos without checking to see if they are true, and this can lead to misinformation spreading quickly online. Skin lesions are those that fall outside the 5 cm radius of the anal opening. -Infection: A bacterial or viral infection can cause inflammation and swell in the perineum. 4) Pedaling Puts You at Risk for Testicular Torsion. Soak in comfortably-hot bath water one to three times per day to help boils surface and drain. The skins surface always contains bacteria. It does not hurt, but I wish I had gotten to treatment sooner as it has now been 5 months. The perineum protects the pelvic floor muscles and the blood vessels that supply the genitals and urinary tract. M. Michiels / Department of Surgery, Heilig Hartziekenhuis, Mol, Belgium, Introduction In other cases, you may feel perineum pain or notice abnormal bleeding or discharge from the perineum. The cytologic and histologic findings from two cases of perineal nodular indurations observed in two. This is where you sit in a tub of warm water for 20 minutes at a time and do this several times a day. Perineal nodular induration (PNI) is a fibroblastic pseudotumor that presents almost exclusively in male cyclists. Imaging has an additional role in the differentiation between bikers nodule and other causes of a perineal swelling. It is in the rub area where I contact the seat. Hello there! A perineal abscess is an infection that causes a painful lump in the perineum. Trofaier, M. L., Schneidinger, C., Marschalek, J., Hanzal, E., & Umek, W. (2016). A perineum lump is a small growth that can occur on the perineum, which is the area between the anus and the vulva or scrotum. Press reports, Our contact and company details Pressure mapping, Setting up your RIDO saddle Perineal procedures - these involve surgery in the area of the perineum which is located between the anus and testicles in men or the anus and lower part of the vagina in women. Perineal descent is often associated with chronic straining in patients with chronic constipation. You can learn more about how we ensure our content is accurate and current by reading our. Needs evaluation: Lumps, bumps, blisters and other skin abnormalities on the genitals need to be evaluated. Your testicles sit between your two fast-moving thighs while cycling, which may result in testicular torsion a freakish ailment involving the twisting of the cord that supplies blood to your balls. By my second year in the saddle, my injuries were veering towards the dire end of the spectrum. The primary role of imaging is to determine the exact extent of the lesion. We use cookies to ensure that we give you the best experience on our website. Perineal raphe Bump Perineal raphe bump is a lump formation on the line of tissues i.e. There are a few things you can do to prevent a perineum lump. Examination No visible abnormality was detected. Along with the causes of dark, Split nails are often caused by an injury such as a stubbed toe or receiving a severe blow to a finger or thumb. PubMed All Healthroid articles adhere to the following standards: This article is written by a medical writer and reviewed by medical professionals. I have developed a lump about the size of a marble in my groin area towards the side of my right leg. Prevention. Symptoms include pain on pressure and when sitting on the saddle, which often forces the athlete to give up riding the bicycle. DOI: Narang S, et al. But its always best to err on the side of caution and get it checked out by a professional. They occur as a result of moisture, pressure and friction where athletes sit on the bike seat (saddle). 6. Sitting on a bicycle seat puts pressure on the perineum, compressing those crucial nerves and arteries. Eur Urol. It also . I ended up having it removed surgically. Would like to know how's your condition now. Additionally, we further monitor the work of writers and contributors with regard to plagiarism or malicious intent. Health news fact-checking is important to ensure that people are getting the right information. Some causes of perineum lumps are common to all sexes. Our team ensure that all the medical articles are reviewed by medical experts in the field before they are published. It is important to see a doctor if you notice any kind of lump on your body so that they can rule out any serious conditions. On palpation, the nodule is solid and sometimes adherent to the adjacent soft tissue. Compression of the perineum can lead to nerve damage, swelling, artery insufficiency (lack of blood flow through the vessel), and even occlusion (blockage) of blood vessels, which in turn can lead to temporary or permanent groin numbness, tingling sensations, decreased penile blood supply, erectile dysfunction ( impotence ), decreased orgasm . One common cause is an abscess, which is a collection of pus that forms around the anus or rectum. Folliculitis and furuncles are infections that may cause perineum pain. Rectal prolapse causes a lump to stick out of your back passage (anus) and this can become quite painful. A perineal hematoma happens when blood pools in the blood vessels under the skin of your perineum, pushing up the skin and causing a lump. Numbness, tingling and tightness may also occur with perineum pain from bicycling. If you have a perineum lump, its important to see your doctor so they can determine the cause and provide appropriate treatment. The Content on this Site is presented in a summary fashion, and is intended to be used for educational and entertainment purposes only. However, it may recur if cycling is continued; it can also affect ones professional cycling career, Cyclist Nodule is a rare tumor that is mostly observed in adults; but, it can be seen in a wider age group, Both males and females are affected and no gender preference is noted, There is no known ethnic group or racial preference, Chronic bicycling - as a sport, a means of daily transport, or as part of ones occupation, Both professional and amateur cyclists are at risk, Cyclist Nodule is the formation of a benign nodule in the perineal region (in both men and women), caused by the effect of constant friction or pressure resulting in injury to the skin and soft tissues of the perineum, This constant rubbing or abrasion of the saddle (of the cycle) against the skin results in microtrauma and leads to the formation of a firm mass, also known as a Bikers Nodule, Due to constant cycling, the benign tumor grows at a slow rate and presents as a firm mass in the perineal region, It may not present any pain or tenderness; but, pain may be felt while cycling, Skin thickening (fibrosis) of the soft tissue tumor may be seen, Occasionally, degeneration of the central part of the tumor can cause the tumor to change from a solid mass to a cystic mass, In males, it may be present as a nodule below the scrotum (on the groove/ridge). Appointments 216.444.5725. A saddle sore in humans is a skin ailment on the buttocks due to, or exacerbated by, horse riding or cycling on a bicycle saddle. When friction breaks the skin, bacteria can enter and cause infection. Finding a lump under your skin is alarming, but most of the time theyre harmless. Other conditions that can cause pain and discomfort in the perineum in people of both sexes are: Perineal pain syndrome or idiopathic perineal pain cause unknown, though research suggests it is often caused by an internal rectal prolapse. Ultrasound shows a hypo-echoic nodule, with absence of any increased power Doppler signal [1]). Minor tears may heal on their own, while major ones may require stitches. Cysts or fatty lumps etc are usually slightly softer to touch and can move around. The differential diagnosis [1, 3, 5] includes abscess, epidermal cyst, (cutaneous) adnexial mass, lipoma, and malignant tumor (soft tissue sarcoma or metastasis). They will then do a physical exam of your entire body, including your perineum. The pudendal nerve is the main nerve in our pelvic area. I am due for my yearly exam in November so I'm sure they will reexamin me to make sure it is gone. One is to avoid sitting for long periods of time. REFERENCES Author information Hope this helps. In particular, malignant transformation of an epidermal cyst in the perineum is extremely rare. 1. Prostatitis can happen when the prostate gland becomes swollen, which can push against the perineum and cause a lump to appear. . Perineal Descent. Bicycling may or may not cause additional discomfort, depending on the precise location of the cyst and how you position yourself on the seat. Anyone can get pain in the pelvis. Try this quick test! Perineal descent is a condition in which the perineum prolapses (bulges down) or descends below the bony outlet of the pelvis. Biker nodule is believed to be a friction phenomenon between the ischium and outer aspect of a racing bicycle seat sitting high up in the perineum near the base of the penis pushing the superficial perineal fascia onto the ischium. First, a quick rundown of our anatomy. REFERENCE Eventually your skin breaks down in the form of painful abrasions. There are, however, other causes of. We present 2 cases of PNI with fine-needle aspiration cytology and immunohistochemistry. Harmless bumps in the genital area include pimples, cysts, angiomas and mollusca. I've had a biopsy within a week of seeing doctor a ct scan and MRI. Overview of Purpuric Rash, a Symptom of Some Conditions, Debra Sullivan, Ph.D., MSN, R.N., CNE, COI, How to Get Rid of Dark Circles Permanently, Debra Rose Wilson, Ph.D., MSN, R.N., IBCLC, AHN-BC, CHT. Pudendal neuralgia is long-term pelvic pain that originates from damage or irritation of the pudendal nerve - a main nerve in the pelvis. ; May 2003. I am having the same problem as you. As in CT, there is no uptake of contrast medium. Lubricate: Chamois cream is designed to reduce friction between your skin and your shorts. The "biker's nodule" is a rarely appearing perineal nodular induration of the cyclist. Used to pass motion with blood because of constipation and prior to having this lump at perineum area. 1. J Chir (Paris). This pressure can cause pain in the perineum that may radiate to the rectum. Perianal Abscess. If left untreated, cellulitis can spread to other parts of the body and cause life-threatening complications. Google Scholar. In males, the perineum is the area between the anus and . You can also use over-the-counter pain medication such as ibuprofen to help with the discomfort. Sometimes its be expected, such as when youre pregnant, and the perineum becomes swollen or painful near the end of the pregnancy. 1Universitts-Hautklinik Heidelberg, Vossstrasse, 2, 69115 Heidelberg. Thankyou. There are a few different risk factors for developing a perineum lump. Some brands also have antibacterial properties but . Most haematomas get better quickly and remember to avoid massage to your injured area. The lesion is believed to result from increased pressure, vibration and friction between the ischial tuberosities and the hard saddle, characteristic of racing cycles or mountain bikes, with constant rubbing of the superficial perineal fascia against the bony structures [15]. You apply chamois cream directly to the pad in your shorts and to your perineum before riding and, although it might initially feel a little strange and squishy, its effectiveness in preventing saddle soreness is almost miraculous. The perineum is the area between the scrotum and the anus in a man. You need to get to a colorectal specialist NOT a general doctor. A forum community dedicated to Road Bike owners and . Second possibility which comes to my mind is of pilonidal cyst . Hassine MABH, et al. Cysts are benign, or noncancerous lumps. A central cystic focus and a zonal pattern are not consistent features of this entity. Whether youre new to cycling or a seasoned pro, you sometimes pay for that time on the seat. Cysts. It is not intended to be and should not be interpreted as medical advice or a diagnosis of any health or fitness problem, condition or disease; or a recommendation for a specific test, doctor, care provider, procedure, treatment plan, product, or course of action. In bikers nodules, signs of inflammation or abscess formation are lacking, and the absence of contrast agent enhancement on MRI excludes malignancy. A wide array of diseases affect the female perineum in adults. It was Small internal cystic areas may be seen as well [1]. I've had it since January and it has increased in size. Sores that look more like boils are usually larger and can be more painful. Most medical experts say that saddle sores are actually boils caused by skin bacteria that invade surface abrasions. Makhanya, N. Z., Velleman, M., & Suleman, F. E. (2014). Apply moleskin with an area cut out around the sore to help keep pressure off the sore itself. BMJ case reports, 2016, bcr2015213087. Perineal injury can occur and cause swelling and/or a lump between anus and scrotum. They're usually caused by blocked hair . What causes Ischial Bursitis? A bikers nodule is a lesser known condition of the perineum that affects cyclists. :). Perineal abscesses are pus-filled sacs that occur when an infection develops in the perineum. 2005-2023 Healthline Media a Red Ventures Company. If you must sit, try to get up and move around every few hours. I go tomorrow for results the perineum is very delicate and mine really hasn't be the same since the birth of my first son 25 yrs ago never ever ignore something that you know in your heart isn't normal. Perineal nodular swelling in a recreational cyclist: diagnosis and discussion. stardust, meg how are you doing? Aggressive angiomyxoma with perineal herniation. A perineum lump may appear where muscles are tight. Some hemorrhoids put pressure on the perineum. Your groin pain from cycling may simply be the result of a poor fit on your bike. Your perineum is the thin layer of skin between your genitals (vaginal opening or scrotum) and anus. The most common symptom of a perineum lump is a small growth or mass that can be felt on the skin. The lesion has been previously known by many synonyms, including third or supernumerary testicle, accessory testicle,perineal hygroma or induration. The condition may be improved by reducing cycling or changing the cycle seat/saddle, With adequate treatment, the prognosis of Cyclist Nodule is generally excellent. First, your doctor may recommend that you take a sitz bath. The signs and symptoms of Cyclist Nodule may include: A diagnosis of Cyclist Nodule is made using the following tools: Although the above modalities can be used to make an initial diagnosis, a tissue biopsy of the tumor may be necessary to make a definitive diagnosis. The inflammation can occur suddenly due to an infection or injury, and in some cases, it may be long term . The perineum is the area between the scrotum and the anus in a man. External hemorrhoids may bleed, itch, or cause pain. The primary role of imaging is to determine the exact extent of the lesion. Special attention should also be given to the pants of the cyclist. I feel as if i have a lump/mass internally between my bottom and my vagina, my bowel habits have changed from regular to constipated, i have piles occasionally, not bothersome,got them at the mo due to pushing. If the cyst becomes infected, you may experience: A tender, painful lump near the vaginal opening. Kjeld V. Andersen, M.D., of Trondheim University Hospital led a study reported in the April 1997 "Acta Neurologica Scandinavica" in which data was collected from 160 participants in a Norwegian annual 335-mile bicycle touring race. vulva, labia and clitoris in women. Wash daily, ideally with a fragrance free soap, and pat the area dry. Blame it on the bike seat. He was concerned so I went to a specialist and did a biopsy. The area may look red and feel painful and be swollen. Benign lumps may not require any treatment, while cancerous lumps will need to be treated with surgery, radiation therapy, or chemotherapy. This takes pressure off the perineum, a region of the body that runs from the anus to the sex organs. But at some point, you may notice a lump on or near your perineum. Some causes of these problems include warmth, moisture, poor hygiene, overzealous hygiene, chafing of the inner labia, oral medications (such as antibiotics) and allergies. The area may look red and feel painful and be swollen. Saddle sores are painful skin lesions that can form on parts of the body that are in contact with a bicycle seat. Message us your query and we'll reply as soon as we can. Womens reviews Amer, T., Thayaparan, A., Tasleem, A., Aboumarzouk, O., Bleehen, R., & Jenkins, B. I have not been aware of the perineum area feeling so solid before, its not painful, thou its an awkward place to feel around. Check your saddle's height. Reducing friction. Shortly prior to seeking medical attention, he noted a tender mass in his perineum. We at Healthroid make sure that by following this simple rule, readers can be confident that theyre getting reliable information. e-mail: filip.vanhoenacker@telenet.be When you compress your pelvis under a bike saddle, a similar phenomenon is happening. CAS In most clinical scenarios, ultrasound will suffice for imaging evaluation. I have the same problem as well. Please remove adblock to help us create the best medical content found on the Internet. It happens when one of your anal glands gets clogged and infected. Causes Of Perineal Pain Possible In Men Or Women. Saddle sores include a range of skin conditions seen in the pelvic/genital region of cyclists. Don't be embarrassed about seeking medical attention. The lesion has been previously known by many synonyms, including third or supernumerary testicle, accessory testicle, perineal hygroma or induration [15]. When friction breaks the skin, bacteria can enter and cause infection. Dermoid cysts are benign tumors consisting of keratinizing squamous cells and contain adnexal structures including hair follicles, sweat glands, and sebaceous glands.1 While pelvic dermoid cysts are common in females, they are exceedingly rare in male patients, especially when isolated to the perineum.2 We present the case of a 22 . Just wanted to know if you got checked it checked by a doctor and if yes, what was it? What is the shape of C Indologenes bacteria? The experts comments are then considered by the editor before the article is finally published. The perineum also protects the nerves used to urinate or have an erection. Cysts are yellowish round lumps under the skin, which feel like a small ball or pebble that can easily be moved around. In some cases, the lump may also bleed or secrete discharge. Once your doctor has confirmed their diagnosis, theyll walk you through the next steps for treating the cause of your perineum lump. or "ischial hygromas" of cyclists, consist of a localized aseptic area of necrosis with pseudocyst. Khler P, Utermann S, Kahle B, Hartschuh W. They are supposed to do a surgery, I have to schedule it monday. But if it develops, one may try considering the following measures: Please visit our Cancer & Benign Tumor Health Center for more physician-approved health information: http://www.dovemed.com/diseases-conditions/cancer/, American Congress of Obstetricians and Gynecologists (ACOG)409 12th Street SW, Washington, DC20024-2188Phone: (202) 638-5577Toll-Free: (800) 673-8444Website: http://www.acog.org, American Cancer Society (ACS)1599 Clifton Road, NE Atlanta, GA 30329-4251Toll-Free: (800) 227-2345TTY: (866) 228-4327Website: http://www.cancer.org, National Cancer Institute (NCI)U.S. National Institutes of HealthPublic Inquiries OfficeBuilding 31, Room 10A0331 Center Drive, MSC 8322Bethesda, MD 20892-2580Phone: (301) 435-3848Toll-Free: (800) 422-6237TTY: (800) 332-8615Email: cancergovstaff@mail.nih.govWebsite: http://www.cancer.gov, http://file.scirp.org/pdf/ASM20120100002_37971387.pdf (accessed on 11/05/2016), https://www.ncbi.nlm.nih.gov/pubmed/11153363 (accessed on 11/05/2016), http://link.springer.com/article/10.1007/s00256-009-0731-9 (accessed on 11/05/2016).