Bacterial Infections
Bacterial infections create a multitude of skin lesions, from pustules, to necrotic nodules, to ulcers. These infections range from the superficial crusted erosions of impetigo to the systemic purpuric plaques…
Lichen Planus and Related Conditions
Lichen planus (LP) and other lichenoid eruptions tend to create characteristic primary lesions and patterns. The pruritic, purple, polygonal, flat-topped papules of LP can appear unmistakably shiny as they reflect…
Contact Dermatitis and Drug Eruptions
Contact dermatitis and cutaneous drug eruptions are both skin conditions triggered by external agents that are either in direct contact with the skin or ingested. Contact dermatitis shares many features…
Connective Tissue Diseases
Cutaneous manifestations of connective tissue diseases are important to identify because they can be a clue to an undiagnosed systemic autoimmune disease. Many lesions, such as those seen in systemic…
Nutritional Diseases
A deficiency or excess of certain required vitamins or minerals can cause specific findings in the skin, hair, nails, and mucosae. This chapter provides images of many of these findings,…
Diseases of Subcutaneous Fat
Panniculitis presents with deep erythematous nodules, induration, and tenderness. Clinical lesions of erythema nodosum can appear as deep-seated, erythematous, tender nodules or can resemble bruises, giving rise to the term…
Seborrheic Dermatitis, Psoriasis, Recalcitrant Palmoplantar Eruptions, Pustular Dermatitis, and Erythroderma
The primary lesion of a papulosquamous disorder is a papule with scale, but because patients often present later in the course of disease, the primary lesions may not be visible,…
Erythema and Urticaria
A wide variety of conditions can present with erythema or urticarial lesions. Whereas many conditions such as urticaria and angioedema lack identifiable surface changes, other diagnoses in this chapter have…
Syphilis, Yaws, Bejel, and Pinta
Syphilis has been dubbed “the great imitator” for its ability to assume varied morphologies. Primary syphilis is characterized by a chancre—a minimally tender, indurated ulcer—or less commonly by syphilitic balanoposthitis….
