Tinea Pedis and Cellulitis of the Lower Extremities

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Tinea Pedis and Cellulitis of the Lower
Extremities

• Alan L. Bisno, MD, FACP
• University of Miami School of Medicine

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Factors Predisposing to Lower Extremity Cellulitis

• Cutaneous disruption
• Trauma, surgery
• Burns
• Ulcers
• Varicella
• Dermatophytes

• Lymphedema, venous insufficiency
• Obesity
• Ischemia
• IV drug abuse
• Immunosuppression

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Microbial Etiology of Eysipelas and Cellulitis

• Classic erysipelas is virtually always due to
  beta-hemolytic streptococci (BHS)
  
• The terms cellulitis and erysipelas are often
  used interchangeably in European literature.
  
• Cellulitis can be due to many microorganisms.
  Most cases are due to BHS or Staphylococcus
  aureus.
  
• Typical lower extremity cellulitis with diffuse
  spreading erythema is usually due to BHS of
  groups A, B,C, and G

Baddour LM, BisnoAL. Amer J Med 1985 79155-159
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Recurrent Cellulitis

• Many patients with an episode of cellulitis
  experience repeated attacks. The percentage of
  patients in whom this occurs is variable,
  depending upon risk factors
• In one study, 77 of such patients had
  abnormalities of lymphatic drainage on
  scintigraphy
  
• It is believed that lymphatic damage is
  progressive with recurrent episodes, thus
  exacerbating the problem

De Godoy JM et al. Lymphology 2000 33 177-180
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Antimicrobial Prophylaxis of Recurrent Cellulitis

• 31 patients with definite or presumptive
  streptococcal cellulitis of the LEs treated with
  1.2 million units of benzathine penicillin G
  monthly for 12 months
• 70 patients who declined and 14 who received
  incomplete prophylaxis served as controls
  
• Recurrences rate was 12.9 in treated patients
  vs 19 in controls (NS)
  
• BPG reduced recurrences in pts. without but not
  in those with predisposing factors
  

Wang J-H et al. CID 1997 25 685-689
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Antimicrobial Prophylaxis of Recurrent Cellulitis

• 40 pts. with venous insufficiency or lymphatic
  congestion who had suffered 2 episodes of
  erysipelas during the previous 3 yrs.
  
• 20 pts. received phenoxymethyl penicillin, 1 to
  2 gm bid (or erythomycin 0.25 to 0.5 gm bid if
  allergic) for a median of 15 mos. with 2
  recurrences vs 8 in 20 untreated controls
  (P0.06)
• Conclusion continuous prophylaxis is indicated
  only in patients with a high recurrence rate.
  

Sjoblom AC et al. Infection 1993 21 390-393
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Tinea Pedis and Lower Extremity Cellulitis
Possible Pathophysiologic Mechanisms

• The recovery of fungi decreases as athletes foot
  becomes progressively more severe.
  
• Aerobic microflora expands as the disease becomes
  more and more serious.
  
• Athletes foot represents a continuum from a
  relatively asymptomatic, scaling fungal eruption
  to a symptomatic, macerated, hyperkeratotic
  process that results from an overgrowth of
  resident organisms if the stratum corneum is
  damaged by preexistent fungi.
• Overgrowth of the same organisms in normal,
  fungus-free interspaces does not produce lesions.

Layden JJ, Kligman AM. Arch Dermatol1978 114
1466-1472
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Tinea Pedis and Lower Extremity Cellulitis
Possible Pathophysiologic Mechanisms

• With progression of the process of
  dermatophytosis, the normal protective skin
  barrier becomes macerated and friable.
  
• As the process continues, the skin becomes
  debilitated and weakens as an effective barrier
  against infection.
  
• Fissures may occur, providing a portal of entry
  for any opportunistic organism in the area,
  resulting in cellulitis.

Day MR et al. Clinics in Podiatr Med Surg. 1996
13 759-766
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Tinea Pedis and Lower Extremity Cellulitis

• Initial studies focused upon patients who had
  undergone saphenous venectomy for coronary bypass
  grafts and subsequently experienced recurrent
  attacks of cellulitis due to BHS
• Many of the infections were due to non-group A
  streptococci
  

Baddour LM, Bisno AL. Ann Intern Med 1982 97
493-496 Greenberg J et al. Ann Intern Med 1982
97 565-566 Baddour LM, Bisno AL. Amer J Med
1985 79 155-159.
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Tinea Pedis and Lower Extremity Cellulitis

• Greenberg et al described 9 men aged 48 to 72
  years who developed cellulitis in the saphenous
  venectomy extremity.
  
• 5 of the 9 patients had recurrent episodes.
• First infection was within 8 mos. post-op in 8
  patients but one was 8.5 years later. Pos. blood
  cultures in 1 pt. yielded BHS.
  
• All 9 had mild to severe tinea pedis of the
  involved leg.
  
• No recurrences after aggressive topical or oral
  antifungal therapy.
  

Greenberg J et al. Ann Intern Med 1982
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Tinea Pedis and Lower Extremity Cellulitis

• A subsequent report detailed 9 patients with
  post-CABG cellulitis, 5 of whom experienced from
  2 to 20 recurrences.
  
• 7 of these patients had tinea pedis, and in 2
  instances, control of dermatophytosis was
  associated with cessation of attacks.

Baddour LM, Bisno AL. JAMA 1984 251 1049-1052
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Tinea Pedis and Lower Extremity Cellulitis

• Semel and Goldin studied 20 patients with LE
  cellulitis. Patients with trauma, peripheral
  vascular disease or chronic leg ulcers were
  excluded.
• Athletes foot was present in 20 (84) of the 24
  episodes studied.
  
• BHS were isolated from ipsilateral toe web spaces
  in 17 (85) of the 20 cases.
  
• No BHS were recovered in 30 controls seen in a
  dermatologists office for treatment of Athletes
  foot but without cellulitis. (P
• Only BHS were recovered more frequently from
  patients than controls.
  

Semel JD, Goldin H. Clin Infect Dis 1996 23
1162-1164.
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Tinea Pedis and Lower Extremity Cellulitis

• 30 Venezuelan patients with erysipelas but in
  otherwise good health
  
• 13/30 (43) had tinea pedis
• In 7/30 (23) tinea pedis was found to be the
  unique predisposing factor
  
• No controls

Roldan YB et al. Mycoses. 2000 43 181-183.
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Tinea Pedis and Lower Extremity Cellulitis

• Prospective but uncontrolled study of 62
  hospitalized adults with cellulitis
  
• Possible predisposing factors
• Dry skin68
• Diabetes mellitus50
• History of cellulitis48
• Peripheral vasc. Dis.40
• Trauma32
• Tinea pedis32
• S/P CABG27

Koutkia P et al. Diag Microbiol Infect Dis 1999
34 325-327
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Tinea Pedis and Lower Extremity Cellulitis

• Case-control study of 167 patients hospitalized
  in 7 French hospitals for LE erysipelas and 249
  hospitalized controls.
  
• In multivariate analysis, significant risk
  factors were disruption of cutaneous barrier
  (ulcer, wound, dermatosis, etc.), lymphedema,
  venous insufficiency, leg edema, overweight.
• Toe-web intertrigo was present in 66 of patients
  and 23 of controls (OR, 6.6, 4.2 to 10.5)
  
• Toe-web intertrigo was a strong risk factor
  (13.9, 7.2 to 27) with a population attributable
  risk of 61.

Dupuy A et al. BMJ 1999 318 1591-1594
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FDA Adverse Event Reports of Cellulitis in
Patients with Tinea Pedis

• The majority of 13 these reports are more
  suggestive of allergy or hypersensitivity to the
  product rather than a true cellulitis.
  

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Unresolved Issues

• What is the risk of normal individuals with tinea
  pedis developing cellulitis at some time in their
  life?
  
• Does this magnitude of risk justify a warning?
• Are the BHS strains recovered from between the
  toes of patients with T. pedis and cellulitis
  truly the organisms responsible for cellulitis? I
  am unaware of reports of the same strain being
  recovered from toe cultures and cellulitis during
  a single attack of cellulitis.

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Issues for the Committee

• Tinea pedis is only one of a number of risk
  factors for the development LE cellulitis, but it
  is one of the most modifiable of such factors.
  
• The committee might wish to add a caution about
  the importance of eradication of tinea pedis in
  patients wth such risk factors as lympedema,
  venous insufficiency, edema of the legs, marked
  obesity, saphenous venetctomy for CABG, or
  previous episodes of cellulitis.