Histoplasmosis Cornelia S. L. Mller, MD Bruce R. Smoller, MD Key Facts Terminology Systemic fungal infection caused by yeast Histoplasma capsulatum var. capsulatum Clinical Issues Widely distributed with endemic occurrence…

Molluscum Contagiosum Talley Whang, MD Chad Jessup, MD, MS Martin C. Mihm, Jr., MD Key Facts Etiology/Pathogenesis Caused by molluscum contagiosum viruses (poxvirus), transmitted by skin-to-skin contact Clinical Issues Primarily…

Dermatophytosis Christine J. Ko, MD Key Facts Terminology Superficial fungal infection secondary to dermatophytes Dermatophytes belong to 3 genera Trichophyton, Epidermophyton, Microsporum Clinical Issues Classic lesion Annular plaque of erythema…

Herpesvirus Wang L. Cheung, MD, PhD Key Facts Terminology Infection by herpes virus (HSV1, HSV2, and VZV) Clinical Issues Clear fluid-filled vesicles that heal well, usually on mucosa sites (lip,…

Secondary Syphilis Gonzalo De Toro, MD Key Facts Terminology SS occurs 4-8 weeks after primary chancre, usually as maculopapular, scaly patches or plaques characteristically involving palms and soles, extremities, trunk,…

Impetigo Irina Margaritescu, MD, DipRCPath Bruce R. Smoller, MD Key Facts Terminology Definition Acute, contagious superficial pyogenic infection of skin caused by staphylococci, streptococci, or both Clinical Issues Epidemiology Peak…

Porokeratosis George R. Collins, DO Joseph Susa, DO Clay J. Cockerell, MD Key Facts Terminology Porokeratosis: Genodermatosis with clonal keratinocytes resulting in clinically and morphologically distinct keratinization disorder Several clinical…

Atypical Mycobacterial Infections Cary Chisholm, MD Key Facts Clinical Issues Tender nodules, abscesses, plaques, or ulcers May be solitary or multiple Erythema M. marinum (swimming pool granuloma, fish tank granuloma)…

Ecthyma Gangrenosum Cary Chisholm, MD Key Facts Terminology Sepsis (classically with Pseudomonas aeruginosa) with skin involvement Clinical Issues Single or multiple painful lesions in immunocompromised patients Red macule that develops…

Ichthyosis Michael W. Peterson, DO Cary Chisholm, MD Clay J. Cockerell, MD Key Facts Terminology Ichthyosis vulgaris (IV) X-linked ichthyosis (XLI) Lamellar ichthyosis (LI) Clinical Issues IV and XLI are…