Fungal Infections OM and Tinea Pedis 2024 PDF

Fungal Infections: Tinea Pedis Onychomycosis Dr Lisa Wright Musculoskeletal Structure & Pathology Lecture outcomes This lecture provides an introduction to: Fungal infections Tinea pedis of skin Onychomycosis of nails For each fungal infection type, we will discuss:...

Fungal Infections: Tinea Pedis Onychomycosis Dr Lisa Wright Musculoskeletal Structure & Pathology Lecture outcomes This lecture provides an introduction to: Fungal infections Tinea pedis of skin Onychomycosis of nails For each fungal infection type, we will discuss: Common causative organisms Aetiologies & pathology Clinical signs & symptoms Diagnosis & differentials Treatment options 2 Fungi Fungi are 1 of the 5 kingdoms of life - into which all living organisms are divided – Monera – Protista – Fungi – Plantae – Animalia There are over 100,000 species of fungi which compromise mushrooms, moulds & yeasts, that digest food outside of their bodies. Many fungi are good/useful, however, some can cause disease in plants & humans. Many medical applications of Fungi have been discovered – including the production of antibiotics from fungi such as penicillin (possibly the most important non- genetic medical breakthrough of the century.) 3  Fungi A fungal organism consists of a mass of threadlike filaments called hyphae, which combine to make up the fungal mycelium. Each hypha is composed of a chain of fungal cells, surrounded by a plasma membrane & cell wall - made of the polysaccharide chitin The hyphae in a fungus branch off of one another to form the mycelium, and are all ultimately connected to the original hypha. The mycelium has a very high surface area to mass ratio which allows the fungus to absorb large quantities of nutrients from its surroundings, after secreting digestive enzymes and digesting its food outside of its body. This ability to intake large quantities of nutrients despite a growing size is one of the prime reasons for the rapidity of mitotic mycelial growth - expanding up to a km of new hyphae per day. 4 Fungal Infections Fungal infection can be broken down into various classifications but from a podiatric perspective the important 3 main classes of fungi are: – Dermatophytes (account for the vast majority of cases of tinea pedis). – Non-dermatophyte moulds. – Yeasts (account for around 1% of cases) Dermatophyte: A fungus that invades only dead tissues of the skin or its appendages (stratum corneum, nails, hair). Dermatophyte fungal hyphae are capable of metabolising keratin and can therefore grow and proliferate in its presence i.e. skin, hair, nails - the human nail and nail bed provide a suitable environment. 5 Dermatophytes 3 main dermatophytes commonly affect the feet: 1. Trichophyton rubrum (T. Rubrum) (accounts for most dermatophytic foot infections) 2. Trichophyton mentagrophytes (T. mentagrophytes) (Trichophyton interdigitale) (2nd most common cause of fungal infections in humans; can also present in animals such as rodents, rabbits, dogs and horses) 3. Epidermophyton floccosum (E. floccosum) (accounts for less than 2% of fungal infections of the feet) In addition, moulds (e.g. Scytalidium hyalinum), yeasts (e.g. Candida albicans), and bacteria (e.g. Corynebacterium minutissimum) may occur secondary to tinea pedis infections. 6 Diseases caused by fungi Human fungal infections in the UK are uncommon in normally healthy persons Confined to conditions such as candidiasis (thrush) & dermatophyte skin infections (athlete's foot). However, in the immunocompromised host, a variety of normally mild or non- pathogenic fungi can cause potentially fatal infections. Furthermore, the relative ease with which people can now visit "exotic" countries provides the means for unusual fungal infections to be imported into this country. 7 Diseases Caused by Fungi Fungal infections (mycoses) are classified depending on the degree of tissue involvement and mode of entry into the host These are: 1. Superficial - localised to the skin, the hair, and the nails. 2. Subcutaneous - infection confined to the dermis, subcutaneous tissue or adjacent structures. 3. Systemic - deep infections of the internal organs. 4. Opportunistic - cause infection only in the immunocompromised. 8 Superficial Mycoses In superficial mycoses infection is localised to the skin, hair & nails e.g. ringworm or tinea - an infection of the skin by a dermatophyte. Ringworm (tinea) infection refers to the characteristic central clearing that often occurs in dermatophyte infections of the skin. Dermatophytes e.g. Trichophyton, Microsporum and Epidermophyton are responsible for the disease. All occur in the UK although tinea infections, other than pedis, are now rare. 9 Superficial Mycoses Candida albicans is a yeast causing candidiasis or "thrush" in humans. Candidiasis typically infects the mouth or vagina. C. albicans is part of the normal flora of the vagina and gastrointestinal tract and is termed a "commensal". However, during times of ill health or impaired immunity the balance can alter and the organism multiplies to cause disease. Antibiotic treatment can also alter the normal bacterial flora allowing C. albicans to flourish. 10  Examples of Superficial Mycoses Tinea pedis Tinea barbae Tinea capitis Thrush of the mouth 11  Subcutaneous Mycoses Infections confined to the dermis, subcutaneous tissue or adjacent structures. May arise following skin wounds & introduction of vegetable matter. Rare & confined mainly to tropical regions. Tend to be slow in onset and chronic in duration. Certain occupation groups appear to have increased risk from infection – E.g. florists, farm workers & others who handle hay and moss The most common symptom is an ulcerative lesion. 12 Systemic & opportunistic fungal infection While systemic infections & opportunistic infections are 2 separate classifications they do tend to go hand in hand. Systemic fungal infections are of course rare, however they become far more likely in people who are immunocompromised hence the term opportunistic. Invasive infections of the internal organs with the organism gaining entry by the lungs, gastrointestinal tract or through intravenous lines. They may be caused by: Fungal lung infection – (i) primary pathogenic fungi or – (ii) by opportunistic fungi that are of marginal pathogenicity but can infect the immunocompromised host. 13 Tinea Pedis 14 Tinea Pedis Tinea pedis is the most common dermatophytosis - may affect up to 70% of adults globally. An example of a superficial mycosis Dividing tinea infections into the body region most often affected can help in identification of the problem. – the foot (tinea pedis: "athlete's foot“ or ‘ringworm’) – the scalp (tinea capitis) – the beard (tinea barbae) – the groin (tinea cruris). ‘jock itch’ Tinea pedis involves the plantar surface & interdigital spaces of the foot – Can include inflammatory and non-inflammatory lesions. 15 Clinical Forms of Tinea Pedis The 3 most common clinical forms of tinea pedis are: 1. Interdigital (most common form) 2. Moccasin type (chronic plantar scaling) 3. Acute vesicular tinea pedis 16  Interdigital Infection May be caused by any of the 3 fungal organisms: T. rubrum, T. mentagrophytes or E. floccosum Presents as macerated skin with web space fissuring & peel Underlying skin often red/ raw in appearance with varying surrounding inflammation. May appear in any web space –most common between the 4th/5th or 3rd/4th digits – warm, occluded, moist environment - can be linked with hyperhidrosis Not uncommon for the interdigital tinea pedis to move out of the web spaces onto the plantar or dorsal surface of the foot. Typically produces itching – aggravated by heat. May produce burning sensation. Patient may scratch area & spread fungus to other parts of the feet/ body. A foul smell may be indicative of secondary yeast or bacterial infection e.g. Pseudomonas (consider broken skin permits portal of entry) 17 Tinea Pedis - Interdigital 18 Examples of Interdigital Infection 19 Tinea Pedis: Affecting Dorsal skin from Digits 20  Moccasin Also known as chronic plantar scaling & is often chronic in nature Distribution is over the sole, heel, and sides of the foot, or what would be covered by a moccasin. Moccasin tinea pedis usually presents as silvery white scales on a red, thickened base which has a well demarcated edge. Occasionally, a single hand may also be involved ‘2-foot, 1-hand presentation’. Onychomycosis often is present May be itchy or asymptomatic. T. rubrum is the main micro organism responsible 21 Tinea Pedis - Moccasin 22 ‘2 feet, 1 hand’ involvement 80% of patients with tinea of the hand also have tinea pedis... could there be a connection? Advise patients to avoid scratching tinea pedis and if they do that they should wash their hands! 23 Acute Vesicular Tinea Pedis Acute vesicular tinea pedis usually presents as vesicles or pustules. Characterised by the rapid onset of vesicles that appear over the plantar or dorsal surface of the foot. With each flare of infection, the sole becomes thicker, and maceration, itching, or secondary infection can develop. Cellulitis or lymphangitis is a potential complication of vesiculobullous tinea pedis. Caused by T. mentagrophytes or Epidermophyton floccosum 24 Pathophysiology Most of the dermatophyte infections are usually confined to the stratum corneum, but can, although rarely extend beyond the stratum granulosum. The dermatophytes invade the keratinised tissue causing the infection that extends to the subcutaneous areas of the body. A chronic infection may result in a hypersensitivity reaction to the fungus and its metabolites. This is commonly known as a dermaphytid reaction. 25 Pathophysiology Tinea pedis is spread via the transfer of skin fragments in various environments. Such surfaces include bathroom floors and communal areas or by towels, sock and shoes. Due to this cross infection among family members is common. Enzymes and other diffusible substances produced by the dermatophytes, including the transepidermal leukocyte chemotaxis, reach the viable layers of the skin and induce the inflammatory response. This is called the colonisation phase and occurs in the stratum corneum. 26 Aetiology (Causes) The factors that can increase the risk of developing a tinea pedis: – Smoking – Perspiring heavily – Working in a humid or moist environment – Wearing socks and shoes that hinder ventilation and don't absorb perspiration – Walking barefoot in damp public places, such as swimming pools, gyms and shower rooms – Diabetes, circulation problems or a weakened immune system 27 Differential Diagnosis: Interdigital Contact dermatitis due to the wearing of shoes and stockings. Hyperhidrosis or candidiasis causes maceration between the toes. Soft corn. Interdigital tinea pedis Soft corn (Heloma Molle) 28 Differential Diagnosis: Moccasin-type Plantar psoriasis Keratoderma Hyperkeratosis Long-standing contact dermatitis of the foot. Moccasin type tinea pedis Contact dermatitis Plantar psoriasis 29 Differential Diagnosis: Acute vesicular Tinea Pedis Pustular psoriasis Epidermolysis bullosa Acute Vesicular Tinea Pedis Pustular psoriasis 30  Diagnosis - Obtaining samples from skin Skin scrapings can be obtained from the affected area and sent to mycology, to allow reliable direct examination by: Mycologists = scientists who study fungus. Medical mycologists = study drugs to cure fungal infections Sample is placed inside a sample pack as shown on the left and then put in a transport envelope as shown on the right. 31 Diagnosis - Skin scraping (KOH test) Before taking a sample, area should be swabbed with an alcohol wipe to remove any medications that may have been applied recently and still exists. Done by scraping off any part of the affected area by using blunt side of number 15 blade attached to a scalpel handle If the lesion has an active edge this is the best site for scraping, otherwise a general scrape of the scaly area is suitable. If any vesicles are present the active fungal cells can be found on the roof of the blister and removed accordingly. Scrapings are collected, and sent to mycology department where they are placed on a slide and a few drops of 10% potassium hydroxide (KOH) solution are added. A cover slip is applied and the slide is heated for examination. 32 Diagnosis - Skin scraping Immediately the branching hyphae of the superficial dermatophytes can be recognised as well as the budding cells of yeasts. The micro organisms can also be cultured - experience is needed to make an accurate interpretation. Sabourauds agar is the most common used. It is a sugar peptide culture medium and samples form the skin can be left in the dark with the Sabourauds agar for approximately two weeks until the culture appears. When the agar has grown the dermatophytes are differentiated due to their differences in spores. 33 Trichophyton rubrum When cultured, T. rubrum appears: white and cottony on the surface. the colony underside is usually red, although some isolates appear more yellowish and others more brownish. Microscopic appearanc Colony Surface ImageColony Underside When grown in ideal conditions in the lab, T. rubrum has the following MICROSCOPIC appearance: sparse microconidia (the club like projections) & absent macroconidia 34 Trichophyton mentagrophytes /interdigitale Predominant microscopy features include abundant microconidia & common macroconidia When cultured, appears white to cream & powdery on surface & cream to dark brown on underside Microscopic appearanc Colony Surface Image Colony Underside 35 Epidermophyton floccosum Predominant microscopy features include absent microconidia & present macroconidia When cultured appears greenish/yellow & powdery on surface & pale brown on underside Microscopic appearan Colony Surface Image Colony Underside 36 Onychomycosis 37  Onychomycosis Onychomycosis (OM) refers to a fungal infection that affects the toenails or the fingernails. May cause pain May be secondary infection with bacteria May be a source of embarrassment. Trauma predisposes to infection. Possible hereditary predisposition. Patients with onychomycosis often have concomitant fungal infections at other sites. 38 Incidence Incidence: – 3 – 8% of the population – Affects all races – Affects men more than women – Adults are 30 times more likely to have OM than children The incidence of onychomycosis has been increasing worldwide, and at present it accounts for almost half of all nail disorders. The increase is believed to be due to many factors: – The aging population – The growing number of immunocompromised patients – The widespread use of occlusive clothing and shoes. 39 Onychomycosis OM is caused by 3 main classes of fungi: – Dermatophytes – Yeasts – Non-dermatophyte moulds. Dermatophytes - including Epidermophyton and Trichophyton (and Microsporum), are by far the most common cause of OM worldwide. 40 Onychomycosis However, yeasts and non-dermatophyte moulds only account for 8% and 2% of OM, respectively. OM may involve any component of the nail unit: – Nail matrix – Nail bed – Nail plate OM is not life threatening, but can cause inconvenience, pain, discomfort, and often serious physical and occupational limitations. Psychosocial and emotional effects resulting from OM are widespread and have a significant impact on the quality of life. 41 Patient History OM is generally asymptomatic Patients therefore usually first present for cosmetic reasons without any physical complaints. As the disease progresses, OM may interfere with standing, walking, and exercising. Patients may complain of paraesthesia, pain, discomfort, and loss of dexterity. They may also have loss of self-esteem and lack of social interaction. A careful history may reveal many environmental and occupational risk factors. 42 Clinical Features: The nail may be: Thickened Brittle, crumbly or ragged Distorted in shape Flat or dull, having lost lustre & shine Yellow, green, brown or black in colour Possibly painful Discoloured, brittle, distorted Possible bad odour 43 Distorted shape Hypertrophic (thickened) & crumbly  Classification OM varies in presentation and the variations can have important implications for treatment. There are 5 main types/ classification of onychomycosis: 1. Distal lateral subungual onychomycosis (DLSO) 2. Proximal subungual onychomycosis (PSO) 3. Superficial white onychomycosis (SWO) 4. Total dystrophic onychomycosis (TDO) 5. Candidal (CO) 44 Distal Lateral Subungual Onychomycosis (DLSO) Most likely to be caused by T. rubrum Most common variant of OM. The fungus generally spreads from plantar skin and invades the underside of the nail via the hyponychium or the distal lateral nail bed. Inflammation occurring in these areas of the nail apparatus causes the typical physical signs of DLSO. 45 Distal Lateral Subungual Onychomycosis (DLSO) – Clinical Features Presents as: – A thickened and opacified nail plate – Nail bed hyperkeratosis – Onycholysis – Discoloration ranges from white to brown. – The edge of the involved area is often dystrophic, while the edge of the nail itself becomes severely eroded. 46 Proximal Subungual Onychomycosis (PSO) More likely to be caused by T. rubrum. The least common subtype, often associated with peripheral vascular disease. The fungi invade the cuticle and the proximal nail fold and then penetrate the nail plate Works proximal to distal. Presents as an area of leukonychia in the proximal nail fold, and it may extend to deeper layers of the nail. The nail plate becomes white proximally and remains normal distally. 47 Superficial White Onychomycosis (SWO) Caused by T. mentagrophytes or some species of non-dermatophyte moulds. Not very common Caused by direct invasion of the surface of the nail plate and by secondary infection of the nail bed and the hyponychium. Usually confined to the toenails, and presents as small, white speckled or powdery patches on the surface of the nail plate. The nail becomes roughened & crumbles easily. 48 Total Dystrophic Onychomycosis (TDO) Usually starts distally and works proximally. As the fungus progresses – hyperkeratosis, causing onycholysis Total dystrophic OM presents as a thickened, opaque, and yellow-brown nail and involves the entire nail plate and matrix. Gradually involved the rest of the nails. 49 Candidal Onychomycosis (CO) Onychomycosis caused by the yeast Candida albicans Can present as several forms. Proximal infection of the nail. Candidal infection may involve both the toenails and the fingernails. It can present as an erythematous swelling of the nail fold (paronychia) or as a separation of the nail plate from its bed (onycholysis). Gross hyperkeratosis of the nail bed and inflammation of the nail fold is observed in chronic mucocutaneous disease. The affected digits take on a bulbous or drumstick appearance, and, sometimes, the entire thickness of nail becomes infected. 50 Moulds Fungi other than T. rubrum, T. mentagrophytes, E. floccosum and Candida, may cause nail disease. These include the moulds: – Scopulariopsis – Scytalidium – Aspergillus – Fusarium – Acremonium – Alternaria Do not drill ANY nails contaminated with fungal infection – esp. these fungi Refer nails contaminated with any of these fungi for avulsion. 51 Causative factors for Onychomycosis The factors that can increase the risk of developing a nail fungal infection: – Family history – Increasing age – Poor health - Diabetes, circulation problems or a weakened immune system (Immunosuppression e.g. HIV, drug induced) – Prior trauma - a minor skin or nail injury, a damaged nail or another infection – Warm climate – Participation in fitness activities - communal bathing – Smoking – Perspiring heavily – Working in a humid or moist environment – Wearing socks and shoes that hinder ventilation and don't absorb perspiration – occlusive footwear 52 Diagnosis The characteristic presentation of OM may lead to diagnosis solely on the basis of the clinical grounds. However, differential diagnoses reveals Lichen planus Psoriasis that many dystrophic nails represent different pathology than OM. Differential diagnosis includes almost all conditions that affect the nails including: – Psoriasis – Lichen planus – Subungual tumours and warts Black nail syndrome Green nail syndrome – Bacterial infection. Both colour changes here are associated with Pseudomonas (bacterial) infection 53 Diagnosis Therefore, lab diagnosis of OM must be confirmed before beginning a treatment regimen. Before obtaining a specimen, the nails must be cleansed with an alcohol swab to remove bacteria and dirt. Nail clipping - Using nail clippers, samples should be taken comprising the whole thickness of the nail, as near as possible to the proximal edge of the lesion. A reasonable sized sample needed. The majority of infections start under the nail, so the subungual debris is particularly valuable. This can be removed with a scalpel or probe. Examination under microscope – nail clippings are soaked in potassium hydroxide (KOH) for 30 – 40 minutes. Most mycology results take 2 days for microscopy & further 3-4 weeks for culture. 54 Diagnosis Superficial scrapings of the nail plate are only useful in cases of superficial onychomycosis, where white crumbly patches are see on the dorsal surface of the nail or in proximal subungual onychomycosis. Up to 50% of nails in which fungus has been seen on direct microscopy fail to grow a pathogen. Therefore if skin lesions are present in soles, toe webs or on palms please send samples from these as well, as they are probably caused by the same pathogen and are more likely to give a positive culture. 55 Tinea Pedis & Onychomycosis Tinea pedis & OM can present together, whereby skin can infect nails and nails can infect skin 56 Treatment Regimes for Tinea pedis & OM 57 Treatment Approaches – Tinea Pedis and Onychomycosis Treatment of cutaneous fungal infections may consist of topical or systemic agents, used singularly or in combination. Usually, treatment is not started until the diagnosis has been confirmed. Most cases of tinea pedis respond to topical agents (i.e. interdigital responds well; moccasin & inflammatory types can require systemic medications) Recurrence is common, especially if untreated onychomycosis serves as a reservoir for re-infection. Example of Topical Terbinafine Example of Oral Anti-fungal 58 Topical Agents Topical treatment alone may be sufficient for non-inflammatory tinea pedis. Can be Fungistatic (inhibit the growth of fungi) or Fungicidal (kill fungi). Topical agents can be divided into 3 major categories: Imidazoles (‘the azoles’) Allylamines Polyenes Plenty other antifungals that fall out with these categories including amorolfine, tolnaftate and Griseofulvin. For tinea pedis, longer term use associated with better outcome, treatment can be 1-4 weeks – night application common as acceptable to patient. Topical agents for OM less effective, unless mild, can take at least a year for resolution (toenail slow growing) – lacquers can be useful & cut the nail back first. Oral treatments preferred. 59 Topical Agents Imidazoles: Imidazole derivatives act by binding to the cytochrome P-450 system and blocking synthesis of ergosterol, a vital component of cell membranes. Fungicidal - Kill a wide range of fungi. Miconazole 2% is indicated for treatment of tinea pedis, tinea cruris, and tinea corporis caused by T rubrum, T mentagrophytes, and E floccosum and also cutaneous candidiasis and tinea versicolor. It is available in cream, ointment, powder, and spray formulations. E.g. Daktarin 60  Topical Agents Allylamines: The mechanism of action of the allylamines is inhibition of squalene epoxidase synthesis. These agents are effective in treatment of dermatophytes and Candida. Fungicidal. Terbinafine is approved for treatment of tinea pedis, tinea cruris, and tinea corporis caused by T rubrum, T mentagrophytes, & E. floccosum. E.g. Lamisil. Polyenes: Binds to ergosterol in the membrane of the fungal cells – causes the fungal cells to ‘starve’. Fungicidal. E.g. Nystatin 61 Additional Topical Agents Tolnaftate: These antifungal medications have various classifications and actions and may be of value in certain clinical situations. Tolnaftate is principally used in tinea pedis. It is active against T rubrum, T mentagrophytes, T tonsurans, E floccosum, and Pityrosporum species but has no activity against Candida. E.g. Tinaderm 62 Additional Topical Agents Corticosteroid and antifungal combinations: In certain clinical situations, topical corticosteroids have been used in combination with topical antifungal agents to add an anti-inflammatory effect. Although corticosteroids can produce initial symptomatic relief, they also reduce the body's natural immunologic response and defences. Corticosteroid therapy requires restrictions on duration of use, location of application, and age of patient (with children usually eliminated from consideration). Because of potential side effects of corticosteroid therapy, use of combination therapy is typically discouraged. 63 Systemic agents (i.e. oral medications) In general, systemic therapy is indicated for treatment of OM and stubborn cutaneous mycoses. Systemic therapy often needed in treatment of moccasin tinea pedis. Common treatment periods are 2 weeks for terbinafine (250 mg once daily) and 2–4 weeks for itraconazole (100 mg once daily), and there is no difference in outcomes between these two medications (Bell-Syer et al 2012). Medicines include Griseofulvin Terbinafine Itraconazole 64 Systemic agents (i.e. oral medications) Terbinafine: This agent acts by inhibiting squalene epoxidase, an essential step in fungal ergosterol synthesis. E.g. Lamisil Oral terbinafine has shown efficacy in treatment of tinea pedis, tinea cruris, tinea corporis, and onychomycoses. Terbinafine is not effective for cutaneous candidiasis or tinea versicolor. Fungicidal. 94% success rate Just 6 weeks treatment for fingernails; 3 months for toenail infection – good compliance Well tolerated. Side effects: diarrhoea, pruritus, dyspepsia, rash, taste disturbance, abdominal pain, and toxic effects on the liver. 65  Systemic agents (i.e. oral medications) Griseofulvin: This agent acts at the cellular level by inhibiting fungal cell-wall synthesis, cellular microtubules, DNA synthesis, and RNA binding. Quite narrow spectrum - It is active against Trichophyton, Epidermophyton, and Microsporum species but ineffective against yeasts and non-dermatophytes. Fungistatic – not fungicidal; therefore requires to be given for prolonged periods – poor compliance. 30% success rate - Has a higher success rate in the treatment of fingernails. It use in the treatment of fungally infected toenails has been less than satisfactory. Re-infection is common & many side effects e.g. GI upset Itraconazole: Fungistatic activity. Slows fungal cell growth by inhibiting synthesis of ergosterol, a vital component of fungal cell membranes. E.g. Sporanox 66 Lasers & photodynamic therapies These treatments may be used for OM – though not well evidenced or available via NHS Lasers - use light ( to heat fungal mycelium producing a fungicidal outcome - Average mycological cure rate is 11% (Gupta et al 2017b). Photodynamic therapies - involves applying a photosensitising agent or dye (such as 5-aminolaevulinic acid) to the fungus and then irradiating it with light. The light activates the photosensitiser that is incorporated into the fungal cells producing free radical oxygen species that lead to cell death (Bhatta et al., 2017, Gupta et al., 2017b). The exact role of photodynamic therapy has not yet been established and further studies are needed. 67 Patient Education For shoes, socks, or hosiery: Change daily Avoid sharing (as with towels) Avoid excessively tight hosiery as promotes moisture Avoid nylon / acrylic socks, wear 100% cotton or wool socks as they can soak up excessive sweat. Wear shoes that fit well and are made of materials that breathe. Avoid barefoot walking in communal spaces (i.e. public showers) Good hygiene - washing feet regularly with soap & water - dry between toes properly. Ensure nails are cut regularly and kept short 68 Summary of Fungal Infections Superficial fungal infections of skin are common in clinical practice. Any skin surface, the mucous membranes, nail plates & beds can be affected. Tinea pedis is the most common fungal infection - may affect up to 70% of global adult population. OM has increasing global incidence & accounts for almost half of all nail disorders. These and many other infections can have varying presentations as well as features that resemble non-fungal disorders (DDx). Tinea pedis can quickly spread to any area of the skin and nails It is important that the treatment is effective to prevent spread and re-infection. The treatment should be continued several months after the clinical signs have gone to decrease the chance of re-occurrence. 69 Further Reading Please read the following sections/chapters, from the online textbook 'Neale's Disorders of the Foot and Ankle' (version 9, Burrow et al (2020)): 'Fungal Infections of the Feet and Nails' (pages 79-85)' from chapter 4 'Dermatological Conditions of the Foot and Leg’ Onychomycosis (Tinea Unguium), (pages 52-53) from chapter 3 'The Skin and Nails in Podiatry ' Any Questions? [email protected] A366 71