ABSTRACT
This chapter discusses inflammatory disorders of the epidermis histologically characterized by vesicle and pustule formation. Systematically assessing only six histologic findings will facilitate classification, and therefore diagnosis of a biopsy specimen with an intraepidermal vesicle or pustule:
1. Determining where the primary split in the epidermis is occurring a. Stratum corneum b. Granular cell layer c. Stratum spinosum d. Basal layer
2. Determining the mechanism of vesicle formation a. Spongiosis b. Acantholysis c. Necrosis d. Cleft e. Pustule formation
3. Looking for specific keratinocyte alterations a. Acantholysis b. Apoptosis/cytolysis c. Necrosis d. Ballooned nucleus
Intracorneal or Subcorneal Intraepidermal Suprabasilar Intrabasilar
Noninflammatory Staphylococcal scalded skin syndrome
Epidermolysis bullosa simplex
Toxic shock syndrome
Acantholytic Pemphigus foliaceus
Pemphigus erythematosus
Herpesvirus infection
Benign familial pemphigus
Pemphigus vulgaris
Pemphigus vegetans
Keratosis follicularis
Transient acantholytic dermatosis
Neutrophil Impetigo; dermatophytosis; candidiasis
Subcorneal pustular dermatosis
Spongiotic, lymphocytic
Eczematous dermatitis (contact, atopic, nummular, drug)
Eosinophil Pemphigus foliaceus Incontinentia pigmenti Pemphigus vulgaris
Pemphigus vegetans
4. Determining the type of inflammatory cells, if present 5. Looking for microorganisms 6. Assessing for the presence of immunoreactants
The primary organization of this chapter will be based on the location of the vesicle or blister formation within the epidermis (Table 1).
