Dermatologic Urgencies and Emergencies: What Every Pathologist Should Know

Abstract

Context.— Fatal dermatologic diseases and ones with high morbidity can occur in the inpatient setting. In such cases, prompt and accurate assessment of a bedside skin biopsy is required. This may be challenging for many pathologists who are not familiar with the complexity of skin pathology and skin terminology within the fields of dermatopathology and dermatology. Objective.— To provide the pathologist with a practical, up-to-date, and “must-know” reference guide on dermatologic urgencies and emergencies from a real-world perspective, highlighting diagnostic pearls, diagnostic pitfalls, and commonly encountered practice gaps. This review will focus on key diseases with which every pathologist should be familiar, including angioinvasive fungal infections, Stevens-Johnson syndrome/toxic epidermal necrolysis, staph-scalded-skin syndrome, acute graft-versus-host disease, bullous pemphigoid, calciphylaxis, Sweet syndrome and its histiocytoid variant, pyoderma gangrenosum, and leukocytoclastic vasculitis, as well as those in their clinical and histopathologic differential. Data Sources.— This review is based on peer-reviewed literature and our personal experiences with these diseases at major academic institutions, including one where a large number of stem cell transplants are performed. This review is unique as it represents collaborative expert opinion from both a dermatopathology and a dermatology standpoint. Conclusions.— This review outlines the critical role that the pathologist plays in the outcomes of patients with dermatologic urgencies and emergencies. Improved patient care will result from prompt and accurate histopathologic diagnoses as well as an open line of communication with the dermatologist.

Stevens–Johnson Syndrome and Toxic Epidermal Necrolysis: A Review of Diagnosis and Management

“…Thus, the diagnosis must be made on clinical parameters. Key features of these disorders are outlined in Table 4 [ 1 , 6 , 13 , 14 , 15 , 16 , 43 , 44 , 45 ].…”

“…SJS/TEN can be distinguished from SSSS by the level of epidermal detachment, which is subcorneal in SSSS and at the dermo-epidermal junction in SJS/TEN. Widespread keratinocytic necrosis is characteristic of SJS/TEN on histopathology [ 43 , 58 ]. The distinction between SJS/TEN and EMM is difficult to make because their histopathology can be identical [ 13 , 16 ].…”

Histiocytoid Sweet syndrome recalcitrant to prednisone causing severe scarring

“…Histiocytoid Sweet syndrome is characterized by a predominate infiltrate of mononuclear cells that have a histiocytic appearance and stain positive for CD68 and myeloperoxidase. A variable number of neutrophils may be present 4 …”

Eosinophilic granulomatosis with polyangiitis: Cutaneous clinical and histopathologic differential diagnosis

“…In contrast, complement can be detected in over half of vasculitis lesions after 72 hours. [22][23][24]…”