Snapshot A veterinarian presents to his primary care physician for a growing pustule on his right forearm. He reports that he often embarks on hikes through fields and forests, bringing back injured animals to treat. He denies any known animal bites or scratches but recalls being pricked by a thorn while hiking. He denies any fevers, chills, nausea, vomiting, conjunctivitis, or sore throat. On physical exam, there is a 0.5 cm pustule with surrounding erythema and multiple scattered nodules along his right forearm. He is prescribed an oral agent for this disease. (Sporotrichosis) Introduction Introduction cutaneous mycoses tinea (dermatophytes) tinea capitis tinea corporis tinea cruris tinea pedis tinea unguium tinea versicolor (pityriasis) subcutaneous mycoses sporothrix schenkii Tinea (Dermatophytes) Introduction organisms are dermatophytes Microsporum spp. Trichophyton spp. Epidermophyton spp. demographics most common fungal infection in the pediatric population common in children transmission direct contact Presentation pruritus Tinea (Dermatophytes) Tinea capitis Tinea corporis ("ringworm") Tinea cruris ("jock itch") Tinea pedis ("athlete's foot") Tinea unguium (onychomycosis) Location Head Scalp Torso Inguinal Feet Nails Clinical characteristics Lymphadenopathy Itchy and scaly plaques with associated alopecia Erythematous annular lesions with central clearing and scaly border Well-demarcated erythematous scaly rash, often symmetric without central clearing Interdigital feet infection Plantar erythema (moccasin distribution) Vesicles, bullae, or pustules Nail thickening Nail discoloration No pain or itching Risk factors African American or Carribbean descent Contact with infected pet Adolescent and adult males Physical activities that cause sweating Occlusive footwear Warm and moist environment Occlusive footwear Warm and moist environment Immunosuppression Communal bathing Treatment Oral antifungals (topicals will not penetrate hair follicles) Topical antifungals Topical antifungals Topical antifungals Topical antifungals Oral antifungals (> 3-4 nails involved or involvement of lunula) Studies potassium hydroxide (KOH) prep with blue fungal stain of scale branching septate hyphae Treatment management approach topical antifungals are often applied without topical steroids if used with steroids, may lead to tinea incognito persistent tinea infection without clinical symptoms due to steroid use may be confused with psoriasis or ezcema oral antifungals griseofulvin itraconazole or fluconazole terbinafine topical antifungals terbinafine cream ketoconazole cream clotrimazole cream Complications bacterial superinfection Tinea versicolor Introduction organism Malassezia spp. (Pityrosporum spp.) yeast-like fungi pathogenesis the infection can damage melanocytes, resulting in hypopigmentation, hyperpigmentation, and pink patches risk factors summer humid weather sweating using body oils immunosuppression Presentation can be pruritic but not as pruritic as dermatophytic infections macules or plaques with irregular borders and overlying fine scale back, chest, neck, and face are commonly affected often present as areas of hypopigmentation inability to tan these areas Studies KOH prep budding cells with multibranching hyphae “spaghetti and meatballs” appearance Wood lamp affected areas will fluoresce Treatment topical selenium sulfide topical antifungals (first-line) ketoconazole oral antifungals (second-line) itraconazole fluconazole Sporotrichosis Introduction organism Sporothrix schenckii dimorphic and cigar-shaped budding yeast with branching hyphae and rosettes of conidia demographics children and young adults transmission direct contact break in skin, often with thorns or splinters via animal bites or scratches risk factors close contact with vegetation (gardening) classically via traumatic introduction with a plant’s thorn (i.e., roses) hunting in the wild immunosuppression Presentation pustule, abscess, or ulcer at site of inoculation nodules along draining lymphatics (nodular lymphangitis) can be disseminated to the rest of the body Studies fungal culture in Sabouraud agar periodic acid-Schiff or methenamine silver stain oval or cigar-shapped budding yeast cells septate hyphae with clusters of characteristic conidia formation (“daisy flowers”) Differential diagnosis tularemia similar to sporotrichosis, tularemia may present with an ulcerated lesion unlike sporotrichosis, tularemia may also have a widespread maculopapular rash, painful conjunctivitis, pharyngitis, and gastrointestinal symptoms Treatment itraconazole first-line potassium iodide adjuvant therapy to itraconoazole amphotericin disseminated disease