Dermatology · PANCE / PANRE

Cutaneous Candidiasis

Written & clinically reviewed by Ryan Busch, PA-C · Updated August 2026 · Report an error

Superficial Candida infection of moist intertriginous skin, diaper area, and nail folds — beefy-red plaques with satellite pustules.

Also known as: candidiasis, candida intertrigo, diaper candidiasis, thrush, paronychia (candidal), candidal balanitis

Overview

Superficial infection of skin or mucous membranes by Candida species (most commonly C. albicans), favoring warm moist sites such as intertriginous folds, diaper area, perlèche (angles of mouth), genital mucosa, and chronically wet hands/nail folds.

Epidemiology

Very common across all ages. Peaks in infants (diaper area), elderly with incontinence, and immunosuppressed patients. Vulvovaginal candidiasis affects ~75% of women at least once in their lifetime.

Try two board-style Cutaneous Candidiasis questions

Real questions from the FirstPassPA bank, with the full explanation. Pick an answer — no signup, no email.

Question 1DermatologyMedium
A 7-month-old infant is brought in for a diaper rash that has persisted for 10 days despite frequent diaper changes and a zinc oxide barrier paste. He recently finished a course of oral amoxicillin for otitis media. On exam, there are beefy-red, moist, confluent plaques over the perineum and buttocks that extend deep into the inguinal skin folds, with a peripheral collarette of scale and scattered satellite pustules at the margins. Which of the following is the most likely diagnosis?
  • AIrritant dermatitis
  • BCandida intertrigo
  • CInverse psoriasis
  • DSeborrheic eczema
Reveal answer & full explanation
Correct answer: B — Candida intertrigo
  • AIrritant dermatitis
  • BCandida intertrigo✓
  • CInverse psoriasis
  • DSeborrheic eczema

Why Candida intertrigo is correct

  • Candidal intertrigo produces beefy-red, moist plaques that INVOLVE the inguinal skin folds, with satellite pustules/papules and a peripheral collarette of scale — the single best distinguishing feature.
  • Recent broad-spectrum antibiotics (amoxicillin) and the warm, occluded, macerated diaper environment are classic risk factors that allow the commensal yeast to undergo hyphal transition and invade.
  • Failure to improve on barrier paste and frequent changes points away from a simple irritant process; KOH would show budding yeast with pseudohyphae, and treatment is a topical antifungal (nystatin or clotrimazole) with each diaper change.

Why the others are wrong

  • Irritant dermatitis — irritant diaper dermatitis is caused by urine/feces contact on convex surfaces; it SPARES the inguinal folds and lacks satellite pustules, and it should respond to barrier paste and frequent changes.
  • Seborrheic eczema — presents with greasy yellow scale and typically also involves the scalp, face, and other flexures; it does not produce satellite pustules.
  • Inverse psoriasis — gives sharply demarcated, smooth red plaques in folds without satellite pustules, usually with a personal or family history of psoriasis.
Question 2DermatologyMedium
A 58-year-old woman with poorly controlled type 2 diabetes presents with a tender, beefy-red moist rash in both inframammary folds. Examination shows confluent erythematous plaques with a peripheral collarette of scale and several small pustules studding the surrounding skin just beyond the plaque edge. A scraping is taken from one of the pustules for potassium hydroxide (KOH) microscopy. Which of the following microscopic findings would best support the most likely diagnosis?
  • ALong septate hyphae, acute-angle branching
  • BBudding yeasts with attached pseudohyphae
  • CShort hyphae with rounded spore clusters
  • DBranching chains of rectangular arthroconidia
Reveal answer & full explanation
Correct answer: B — Budding yeasts with attached pseudohyphae
  • ALong septate hyphae, acute-angle branching
  • BBudding yeasts with attached pseudohyphae✓
  • CShort hyphae with rounded spore clusters
  • DBranching chains of rectangular arthroconidia

Why Budding yeasts with attached pseudohyphae is correct

  • A beefy-red intertriginous plaque with a peripheral collarette of scale and satellite pustules in a moist fold of a poorly controlled diabetic is classic cutaneous candidiasis (intertrigo).
  • KOH microscopy of Candida shows budding yeasts (blastoconidia) together with pseudohyphae, the finding that reflects the yeast-to-hyphal transition driving tissue invasion.
  • Diagnosis is usually clinical; KOH is the confirmatory bedside test, and fungal culture is reserved for refractory disease or species identification.

Why the others are wrong

  • Long septate hyphae, acute-angle branching points to a dermatophyte such as tinea cruris, which shows a sharp scaly advancing border with central clearing, spares the scrotum, and lacks satellite pustules in the fold.
  • Short hyphae with rounded spore clusters is the spaghetti-and-meatballs pattern of tinea (pityriasis) versicolor from Malassezia, which causes hypo- or hyperpigmented macules on the trunk, not a satellite-pustule intertrigo.
  • Branching chains of rectangular arthroconidia describe dermatophyte arthrospores rather than the yeast-and-pseudohyphae mix of Candida, so they would not confirm candidal intertrigo.
🔒 Free preview limit reached

Keep reading — start your free trial

You've read your 2 free diagnosis previews. Create your free account to unlock the full Cutaneous Candidiasis outline — plus all 514 diagnoses, 6,500+ board-style questions, flashcards, and an AI tutor. Your 7-day free trial includes everything, and there's no credit card required.

Start your 7-day free trial → Sign in
Free to start · No credit card · Cancel anytime

Risk factors

  • Moisture, occlusion, obesity, incontinence, diaper occlusion
  • Diabetes mellitus (particularly poorly controlled)
  • Pregnancy, oral contraceptives (vulvovaginal)
  • Broad-spectrum antibiotics
  • Systemic corticosteroids, immunosuppression, HIV, chemotherapy
  • Topical or inhaled corticosteroids (thrush, intertrigo)
  • Frequent wet work (paronychia, hand candidiasis)
  • Iron deficiency, hypothyroidism, hypoparathyroidism (chronic mucocutaneous candidiasis)

Pathophysiology

Candida is a commensal in oral, GI, and vaginal flora. Disruption of skin barrier, mucosal microbiome, or local/systemic immunity allows yeast-to-hyphal transition and tissue invasion. Inflammatory response produces erythema, satellite pustules, and pseudomembrane formation on mucosa.

Clinical presentation

Symptoms

  • Burning, itching, soreness in affected area
  • Vulvovaginal: thick white 'cottage cheese' discharge, pruritus, dyspareunia
  • Oral: white plaques that scrape off (pseudomembranous), painful red atrophic mucosa (erythematous/atrophic), or angular cheilitis (perlèche)
  • Paronychia: tender swollen erythematous nail fold, chronic

Signs / physical exam

  • Intertrigo: beefy-red erythematous moist plaques with peripheral collarette of scale and satellite pustules/papules — axillae, inframammary, inguinal, abdominal panniculus, intergluteal cleft
  • Diaper candidiasis: beefy-red plaques INVOLVING inguinal folds with satellite pustules (vs irritant diaper dermatitis which spares folds)
  • Oral thrush: white curd-like plaques that scrape off, leaving erythematous base; perlèche (angular cheilitis); median rhomboid glossitis
  • Vulvovaginal: erythema, edema, fissures, thick white discharge adherent to walls
  • Candidal balanitis: erythematous papules and pustules on glans with white exudate
  • Chronic paronychia: erythematous swollen proximal nail fold, loss of cuticle, secondary nail dystrophy

Classic findings

Beefy-red plaque with satellite pustules in skin folds; INVOLVES skin folds (unlike irritant or tinea); 'cottage cheese' vaginal discharge.

Differential diagnosis

  • Tinea cruris — Sharp scaly border, central clearing, SCROTUM SPARED; KOH septate hyphae
  • Inverse psoriasis — Sharply demarcated red plaques, no satellite pustules, family history of psoriasis
  • Seborrheic dermatitis (intertriginous) — Greasy scale, also affects scalp/face
  • Erythrasma — Coral-red Wood's lamp fluorescence, brown thin patches; Corynebacterium
  • Hailey-Hailey disease — Recurrent painful intertriginous erosions and fissures; autosomal dominant; family history
  • Contact dermatitis (diaper) — Spares the inguinal folds (where urine/feces don't contact); no satellite pustules
  • Lichen sclerosus — Porcelain-white atrophic genital plaques with figure-of-eight distribution

Diagnostic workup

Diagnostic criteria

Clinical presentation + KOH/culture in characteristic site.

Labs

  • Clinical diagnosis usually sufficient
  • KOH preparation: budding yeasts with pseudohyphae
  • Fungal culture if refractory or to identify species (e.g., C. glabrata, C. krusei resistant to fluconazole)
  • Wet mount + pH for vaginal candidiasis (pH normal 3.8-4.5 in candida; >4.5 suggests BV/trichomonas)
  • HIV testing and diabetes screening for recurrent or refractory adult disease
  • TSH, ferritin, calcium if chronic mucocutaneous candidiasis suspected

Imaging

  • Not indicated

Diagnostic algorithm

SiteLesion / SignFirst-Line Therapy
Skin folds (intertrigo)Beefy-red plaques + satellite pustulesTopical nystatin or clotrimazole; keep dry
Diaper areaErythema involving folds + satellite lesionsTopical nystatin/clotrimazole with each change
Oral (thrush)White curd plaques that scrape offNystatin suspension; oral fluconazole if moderate-severe
VulvovaginalCottage-cheese discharge, pH 3.8-4.5Fluconazole 150 mg PO × 1 or topical azole
EsophagealDysphagia, odynophagia (HIV)Oral fluconazole 200-400 mg × 14-21 d
Paronychia (chronic)Wet-work-related swollen nail foldKeep dry; topical antifungal + low-potency steroid
Cutaneous candidiasis variants and first-line therapy.

Treatment

First-line

  • Cutaneous intertrigo: topical antifungal — nystatin cream/ointment, clotrimazole 1%, miconazole 2%, ketoconazole 2% — BID until clear plus 1 week; keep area DRY (absorbent powder, hair dryer on cool, breathable fabrics, weight loss for chronic intertrigo)
  • Diaper candidiasis: nystatin or clotrimazole ointment with each diaper change; frequent diaper changes, air time, barrier paste (zinc oxide)
  • Oral thrush: nystatin suspension 4-6 mL swish-and-swallow QID × 7-14 days, OR clotrimazole troches 10 mg 5x/day, OR oral fluconazole 100-200 mg daily × 7-14 days (for moderate-severe disease)
  • Vulvovaginal (uncomplicated): single dose oral fluconazole 150 mg OR topical azole (clotrimazole, miconazole) intravaginal 1-7 days
  • Vulvovaginal (severe/recurrent): fluconazole 150 mg every 72 h × 3 doses; maintenance fluconazole 150 mg weekly × 6 months for recurrent disease (≥4 episodes/year)
  • Candidal balanitis: topical clotrimazole + treat sexual partner; circumcision occasionally for refractory disease
  • Chronic paronychia: keep hands dry, avoid wet work, topical antifungal + low-potency steroid; oral fluconazole 150 mg weekly for severe

Esophageal / immunocompromised

  • Oral fluconazole 200-400 mg daily × 14-21 days
  • Echinocandin (caspofungin, micafungin) or amphotericin B for resistant species or systemic candidiasis
  • Address underlying immunosuppression

Chronic mucocutaneous candidiasis

  • Long-term oral azole therapy
  • Evaluate for autoimmune polyendocrine syndrome type 1 (APECED), STAT1 gain-of-function mutations, HIV

Second-line / adjunct

  • Address underlying risk factors: glycemic control, weight loss, eliminate occlusion, dry intertriginous areas
  • Probiotics — limited evidence
  • Fluconazole-resistant species (C. glabrata): boric acid 600 mg vaginal capsule nightly × 14 days, nystatin vaginal tablets, or echinocandin

Complications

  • Recurrent infection, especially in diabetic and immunocompromised patients
  • Bacterial superinfection of macerated skin
  • Candidal sepsis in critically ill (rare from skin source)
  • Esophageal candidiasis in HIV/immunocompromised — dysphagia, odynophagia
  • Fluconazole adverse effects: hepatotoxicity, QT prolongation, teratogenicity (high dose), drug interactions

PANCE pearls

  • Diaper candidiasis INVOLVES the inguinal folds; irritant diaper dermatitis SPARES the folds — single best distinguishing feature.
  • Tinea cruris spares the scrotum; candida involves it.
  • Recurrent vulvovaginal candidiasis (≥4 episodes/year) warrants checking glucose and HIV status.
  • Always confirm Candida species in recurrent disease — C. glabrata and C. krusei are often fluconazole-resistant.
  • Oral thrush in an adult without obvious risk factors (denture, inhaled steroid) should prompt HIV testing.

References

  • IDSA 2016 — Clinical Practice Guideline for the Management of Candidiasis: 2016 Update (Pappas et al., Clin Infect Dis 2016)
  • CDC STI 2021 — CDC Sexually Transmitted Infections Treatment Guidelines, 2021 — Vulvovaginal Candidiasis (Workowski et al., MMWR Recomm Rep 2021)
  • AAD — Diagnosis and Management of Common Cutaneous Fungal Infections (AAD review series)

Practice Dermatology questions on FirstPassPA

Turn this outline into retention. 6,500+ board-style questions with an AI tutor that explains every answer — free to start, no card required.

Answer the 2 free questions above → Get today's free question →

Related Dermatology diagnoses

Acne VulgarisRosaceaAtopic Dermatitis (Eczema)Allergic and Irritant Contact DermatitisSeborrheic DermatitisPsoriasisLichen PlanusPityriasis RoseaTinea Infections (corporis, capitis, pedis, cruris, versicolor)ScabiesPediculosisImpetigoHerpes Zoster (Shingles)Verrucae (Warts, HPV)

Differentials & related conditions

Lichen Sclerosus (Genital)

Educational use only. This outline is a study aid for PA students and is not medical advice or a substitute for clinical judgment. FirstPassPA is an independent study tool and is not affiliated with, endorsed by, or sponsored by NCCPA or PAEA. PANCE® and PANRE® are registered trademarks of the National Commission on Certification of Physician Assistants; End of Rotation™ is a program of the Physician Assistant Education Association.