Differential Diagnosis in Dermatopathology

Allergic contact dermatitis vs. Irritant contact dermatitis

Papules on skin and mucous membranes that result from infection of keratinocytes by different types of papillomavirus and classified according to their silhouettes, to wit, papillated (verrucae vulgares on different sites such as volar skin, i.e., v…

Differential Diagnosis in Dermatopathology

Differential Diagnosis

Dilated pore Pilar sheath acanthoma 1. An infundibular cyst fundamentally 1. A neoplasm with follicular and sebaceous differentiation fundamentally 2. Step sections reveal an infundibular cyst and, often, signs of rupture of it 2. Step section…

Differential Diagnosis in Dermatopathology

Discussions

The alopecias of discoid lupus erythematosus and of lichen planus share several findings histopathologic, among them being perivascular, peri-infundibular, and perifollicular infiltrates of lymphocytes, vacuolar alteration at the junction between in…

Differential Diagnosis in Dermatopathology

Lichen simplex chronicus vs. Hypertrophic lichen planus

Papules on skin and mucous membranes that result from infection of keratinocytes by different types of papillomavirus and classified according to their silhouettes, to wit, papillated (verrucae vulgares on different sites such as volar skin, i.e., v…

Histologic Diagnosis of Inflammatory Skin Diseases

Psoriasis

Psoriasis Presentation stereotypical Age and sex Persons of any age and of both sexes Distribution of lesions Localized, e.g., single papule or plaque, or universal, i.e., erythroderma; between these extremes, a preference for elbows and knees, scal…

Differential Diagnosis in Dermatopathology

Discussions

Alopecia areata and trichotillomania have several attributes histopathologic in common, namely, some follicles in catagen and often in telogen, long fibrous tracks behind shortened follicles and, in sections from some specimens, and hardly any periv…

Differential Diagnosis in Dermatopathology

Lichen amyloidosis vs. Colloid milium

Papules on skin and mucous membranes that result from infection of keratinocytes by different types of papillomavirus and classified according to their silhouettes, to wit, papillated (verrucae vulgares on different sites such as volar skin, i.e., v…

Differential Diagnosis in Dermatopathology

Discussions

Differentiation histopathologic of verruca vulgaris from keratoacanthoma and vice versa may be exceedingly difficult because the two proliferations with different appearances clinical and behaviors biologic have so many findings histopathologic in c…

Differential Diagnosis in Dermatopathology

Ichthyosis vulgaris vs. X-linked ichthyosis

Papules on skin and mucous membranes that result from infection of keratinocytes by different types of papillomavirus and classified according to their silhouettes, to wit, papillated (verrucae vulgares on different sites such as volar skin, i.e., v…

Differential Diagnosis in Dermatopathology

Epidermolytic hyperkeratosis vs. Plane wart

Papules on skin and mucous membranes that result from infection of keratinocytes by different types of papillomavirus and classified according to their silhouettes, to wit, papillated (verrucae vulgares on different sites such as volar skin, i.e., v…