Dermatology · Fungal Infections
The facts most likely to be tested
Cutaneous candidiasis presents as a bright red, pruritic rash in intertriginous areas such as the axilla, groin, or inframammary folds.
The hallmark physical finding is the presence of satellite lesions, which are small, erythematous papules or pustules surrounding the main rash.
Diagnosis is confirmed via KOH preparation showing pseudohyphae and budding yeast.
Risk factors for development include obesity, diabetes mellitus, immunosuppression, and recent broad-spectrum antibiotic use.
The primary treatment for localized cutaneous candidiasis is topical azoles such as clotrimazole or nystatin.
Maintaining a dry environment and using barrier creams are essential adjunctive measures to prevent recurrence in skin folds.
Severe or refractory cases may require oral fluconazole to achieve clinical resolution.
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A 52-year-old female with a history of type 2 diabetes mellitus presents to the clinic complaining of a persistent, itchy rash under her breasts. Physical examination reveals a bright red, macerated plaque in the inframammary fold with several small, erythematous papules located just beyond the border of the main lesion. The patient reports no recent changes in soap or detergent. A KOH preparation of a skin scraping is performed.
What is the most likely diagnosis and the most appropriate initial treatment?
Cutaneous candidiasis; topical clotrimazole.
The presence of satellite lesions in an intertriginous area is pathognomonic for cutaneous candidiasis, which is treated with topical antifungal agents.
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Etiology / Epidemiology
Caused by Candida albicans in warm, moist environments. High risk in obesity, diabetes mellitus, and antibiotic use.
Clinical Manifestations
Pruritic, beefy-red rash with satellite lesions in intertriginous zones. Intertrigo is the classic presentation.
Diagnosis
KOH preparation showing budding yeast and pseudohyphae is the gold standard.
Treatment
Keep area dry; topical clotrimazole is first-line. Avoid systemic steroids.
Prognosis
Excellent with hygiene; secondary bacterial infection is the primary complication.
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Epidemiology & Etiology
Overgrowth of commensal Candida albicans occurs when skin barrier integrity is compromised. Predisposing factors include immunosuppression, hyperglycemia, and prolonged moisture exposure. Common in patients wearing occlusive clothing or those with incontinence.
Pertinent Anatomy
Predominantly affects intertriginous areas where skin surfaces appose. Common sites include the inframammary folds, axillae, inguinal creases, and the interdigital spaces.
Pathophysiology
Candida thrives in warm, macerated skin environments. The organism produces proteases and phospholipases that facilitate tissue invasion. The inflammatory response leads to the characteristic erythematous, macerated plaques.
Clinical Manifestations
Presents as a bright, beefy-red rash with sharp borders. The hallmark is the presence of satellite papules and pustules beyond the main plaque. Red flag: If lesions are refractory, consider underlying diabetes mellitus or HIV.
Diagnosis
The KOH preparation is the diagnostic gold standard, revealing pseudohyphae and budding yeast. A fungal culture is rarely required unless the diagnosis is unclear. Wood's lamp examination is typically negative, helping distinguish it from erythrasma.
Treatment
First-line therapy is topical clotrimazole or nystatin powder. Keep the affected area clean and dry to prevent recurrence. Avoid topical corticosteroids as they can exacerbate fungal growth and mask clinical signs.
Prognosis
Prognosis is excellent with proper hygiene and topical therapy. Secondary bacterial infection (e.g., Staphylococcus aureus) is the most common complication. Recurrence is frequent if the underlying moisture-trapping environment is not corrected.
Differential Diagnosis
Erythrasma: coral-red fluorescence on Wood's lamp
Tinea corporis: annular lesions with central clearing
Inverse psoriasis: lacks satellite lesions, involves gluteal cleft
Seborrheic dermatitis: greasy yellow scales on scalp/face
Contact dermatitis: history of exposure to irritant/allergen