Inflammatory Dermatopathology Introduction: Approach to Spongiotic, Psoriasiform, Interface Patterns

This video provides a guide to diagnosing inflammatory skin conditions in dermatopathology. Led by Dr. Emily DeSantis and Dr. Davis.

The key topics covered include:
• Systematic Evaluation
• Spongiotic Dermatitis
• Psoriasiform Dermatitis
• Interface Dermatitis

Presentation slides here:
https://sagis.pathpresenter.net/publi...

00:00 - Welcome to Sagis Dermpath with Davis & DeSantis
11:40 - Dyshidrotic dermatitis
13:28 - Dermatophytosis
14:16 - Dermatophytosis (PAS stain)
16:34 - Eosinophilic spongiosis (drug reaction)
18:42 - Prurigo nodularis
20:44 - Psoriasis
25:28 - Psoriasiform drug reaction
27:53 - Psoriasiform mycosis fungoides
29:02 - Psoriasiform nutritional deficiency (zinc)
35:43 - Erythema multiforme
36:21 - Fixed drug eruption
38:20 - Fixed drug eruption
41:07 - Subacute lupus erythematosus
45:14 - Discoid lupus erythematosus
46:14 - Lichen planus
47:26 - Lichenoid drug eruption
48:29 - Benign lichenoid keratosis
48:36 - Lichen striatus

Chapter 1: Introduction and Goals [00:12]
The video introduces the topic of inflammatory skin lesions in dermatopathology.

Chapter 2: Importance of Communication and Biopsy Technique [01:23]
Communication between clinicians and pathologists. Key factors for an accurate diagnosis include a detailed clinical history, biopsy technique (preferring punch over shave), and the clinical differential diagnosis.

Chapter 3: Systematic Approach to Biopsy Evaluation [03:39]
Systematic method for evaluating biopsies, which involves starting at low power and working from the top down (stratum corneum, epidermis, dermis).

Chapter 4: Commonly Used Terms in Inflammatory Dermatoses [05:49]
Terms used in inflammatory dermatopathology: acanthosis, psoriasiform hyperplasia, orthokeratosis, parakeratosis, and dyskeratosis.

Chapter 5: Categories of Inflammatory Dermatoses & Focus on Spongiotic Dermatitis [07:06]
This chapter introduces the main categories of inflammatory skin conditions and focuses on spongiotic dermatitis. It explains the concept of spongiosis and its clinical presentation in acute and chronic forms.

Chapter 6: Differential Diagnosis and Examples of Acute Spongiotic Dermatitis [11:22]
The speaker discusses the differential diagnosis for acute spongiotic dermatitis, using a case of dyshidrotic eczema and another of tinea infection to illustrate how clinical and special stains are used to arrive at a final diagnosis.

Chapter 7: Spongiotic Dermatitis with Intraepidermal Eosinophils (Eosinophilic Spongiosis) [15:01]
This section covers a specific subtype of spongiosis characterized by eosinophils. It provides a differential diagnosis that includes arthropod reactions, drug reactions, and bullous pemphigoid, and presents a case of a drug reaction.

Chapter 8: Subacute and Chronic Spongiotic Dermatitis [17:55]
The video delves into the features of subacute and chronic spongiotic dermatitis, with a case of prurigo nodularis demonstrating the effects of chronic rubbing.

Chapter 9: Psoriasiform Dermatitis [21:31]
This chapter introduces psoriasiform dermatitis and uses psoriasis as the prototype, explaining its classic histologic features like regular epidermal hyperplasia and suprapapillary plate thinning.

Chapter 10: Differential Diagnosis of Psoriasiform Dermatitis [23:41]
The speaker provides a comprehensive differential for psoriasiform dermatitis, including chronic spongiotic dermatitis, pityriasis rubra pilaris, psoriasiform drug reactions, and nutritional deficiencies. It uses case examples to highlight the distinguishing features of each.

Chapter 11: Interface Dermatitis - Introduction and Vacuolar Change [30:23]
This section introduces interface dermatitis, which is centered at the dermal-epidermal junction. It defines the two main subtypes, vacuolar and lichenoid, and uses erythema multiforme as an example.

Chapter 12: Examples of Vacuolar Interface Dermatitis (Erythema Multiforme & Fixed Drug Eruption) [32:19]
The video uses cases of erythema multiforme and fixed drug eruption to demonstrate the histologic features of vacuolar interface dermatitis, emphasizing the presence of individual apoptotic cells and pigment incontinence.

Chapter 13: Interface Dermatitis - Lupus Erythematosus [39:03]
This chapter focuses on Lupus Erythematosus (LE), detailing the general histologic features and highlighting specific findings for Discoid LE, such as follicular plugging and a thickened basement membrane.

Chapter 14: Interface Dermatitis - Lichenoid Pattern (Lichen Planus and Differentials) [43:17]
The video uses Lichen Planus as the prototype for lichenoid dermatitis, explaining its characteristic band-like infiltrate and sawtooth rete ridges. It also discusses look-alikes like lichenoid drug reactions and lichenoid keratosis.

Chapter 15: Conclusion and Future Topics [49:50]
Preview of upcoming topics, including pustular, granulomatous, and vesicular bullous dermatitis.

EDUCATION
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