Tinea Pedis

Question 1

What is Tinea Pedis?

Answer 1

• Commonly known as Athletes Foot
• Dermatophyte infection of the skin
• Most common type of fungal infection
• More common in men

Question 2

What is the aetiology of Tinea Pedis? (Host factors)

Answer 2

• Immunosuppression:
  
  • Chemotherapy
  • Immunosuppressive drugs
  • Steroids
  • Organ transplant
  • AIDS
• Poorly controlled Diabetes Mellitus
• Obesity/Age
• Occlusive footwear (often from profession)

Question 3

What is the aetiology of Tinea Pedis? (Local factors)

Answer 3

• Moist conditions
• Occlusive footwear / shared footwear
• Poor foot hygeine
• Hyperhidrosis
• Shared towels
• Public showering / barefoot walking
• Trauma

Question 4

What Dermatophytes cause Tinea Pedis?

Answer 4

• Dermatophytes:
  
  • Microsporum
  • Epidermophyton
    
    • E.Floccosum
  • Tricophyton
    
    • T.Rubrum*
    • T.Mentagrophytes
    • T.Interdigitale

*T.Rubrum accounts for the majority of cases in the UK

Question 5

What is the pathology of Tinea Pedis?

Answer 5

• Dermatophytes infect the Stratum Corneum
• Inhabit Keratin as branching hyphae via enzyme secretion, to breakdown keratin
• This leads to increased proliferation, which can result in scaling, and epidermal thickening
• Dermatophytes are unable to penetrate further in an immunocompetent host
• Inflammation is seen due to:
  
  • Metabolic products of the fungus
  • Delayed hypersensetivity reaction

Question 6

What is Hypha, and why is it important with Tinea Pedis?

Answer 6

• Hypha is a branching filament off a fungus (including Tinea Pedis), which make up the Mycelium
• Hypha is important as it inhibits Keratinocytes

Question 7

What are Clinical Symptoms of Tinea Pedis? (Generic)

Answer 7

• Itching / Discomfort
• Scaly Patches
• Vesicles (little small blisters)
• Dry, powdery white lines

Question 8

What are Clinical Features of Interdigital Tinea Pedis?

Answer 8

• T.rubrum
• T.Mentagrophytes
• T.Interdigitalis
• E.Floccosum
• Normally starts between 4th and 5th digit
• Itching / burning / odour
• Fissures
• Scaling
• Erythema

Question 9

What are Clinical Features of Interdigital Dermatophytosis Complex?

Answer 9

• Dry appearance
• Can be pruritic (itchy skin)
• Epidermis may fissure

Question 10

What are Clinical Features of Interdigital Dermatophytosis Simplex?

Answer 10

• Wet appearance
• Pruritic/Burning/Malodour might be present
• Peeling/Maceration/Fissures
• Secondary bacterial infection may be present

Question 11

What are clinical Features of Moccasin Tinea Pedis?

Answer 11

• T.Rubrum
• Asymptomatic
• Dry/powdery scaling
• Red appearance
• Often has associated Onychomychosis
• Erythema may be present

Question 12

What are Clinical features of Vesicular Tinea Pedis?

Answer 12

• T.Mentagrophtes var. Interdigitalis
• Interdigital & Plantar (medial longitudinal arch area) & dorsal foot
• Inflamed appearance
• Can burst brown/red exudate
• Skin becomes scaly