PERIVASCULAR AND DIFFUSE DERMATITIS, NON-INFECTIOUS FOLLICULITIS AND PERIFOLLICULITIS

Question 1

Answer 1

URTICARIA

• Sparse perivascular & interstitial infiltrate (LYMPHOCYTES, NEUTROPHILS,EOSINOPHILS)
• +/- Dermal edema
• Almost normal looking skin biopsy

Question 2

Answer 2

PIGMENTED PURPURIC DERMATOSIS

• Perivascular infiltrate composed of lymphocytes
• Extravasated erythrocytes
• Siderophages/ marked hemosiderin deposition

Variable mild epidermal changes: Spongiosis, Lymphocyte exocytosis

Question 3

What stain can be requested to highlight siderophages? What condition are these cells seen?

Answer 3

Perl’s Stain
Pigmented Purpuric Dermatosis

Question 4

Answer 4

POLYMORPHOUS LIGHT ERUPTION

• Superficial and Deep
• Lymphocyte predominant
• Marked papillary edema

Question 5

Answer 5

ARTHROPOD BITE HYPERSENSITIVITY

• Wedge-shaped infiltrate

Question 6

Answer 6

ERYTHEMA ANNULARE CENTRIFUGUM

• Perivascular lymphohistiocytic infiltrate

• can present with superficial or deep variant
• Photos shown are superficial vaiant
• Deep variant lacks spongiosis and parakeratosis

Question 7

Answer 7

POST-INFLAMMATORY PIGMENT ALTERATION

• Normal looking epidermis
• Mild Perivascular lymphohistiocytic infiltrate
• Numerous Melanophages present in the superficial dermis

Question 8

Answer 8

VITILIGO

• Absence of melanocytes in the dermo-epidermal junction
• Normal looking epidermis
• Mild Perivascular lymphohistiocytic infiltrate

Question 9

Normal melanocyte to keratinocyte ratio

Answer 9

1:4-1:10

Question 10

Stains to highlight melanocyte

Answer 10

S100, SOX HMB-45, MART-1, Melan-A, MITF

Question 11

Stains to highlight melanin

Answer 11

Fontana-Masson, Silver nitrate

Question 12

Answer 12

TUMID LUPUS

• Normal looking epidermis
• Dense lymphohistiocytic infiltrate surrounding adnexa
• Superficial and Deep Perivascular lymphohistiocytic infiltrate
• Mucin highlighled by Alcian Blue

Question 13

Marked papillary edema

Answer 13

SWEET’S SYNDROME

No fibrinoid degeneration or necrosis

Question 14

Diffuse neutrophilic infiltrates, extensive suppuration

Answer 14

PYODERMA GANGRENOSUM

• Fibrinoid deposition of blood vessels and Endothelial swelling
• Follicular or perifollicular inflammation with micro-abscess formation - differentiates it from sweet’s

Question 15

Answer 15

MASTOCYTOSIS – URTICARIA PIGMENTOSA

• Loosely scattered or grouped mast cells in dermis
• Basal hyperpigmentation

Question 16

Answer 16

MASTOCYTOSIS - MASTOCYTOMA
**Diffuse Cutaneous Mastocytosis and Cutaneous Mastocytoma **

• Nodular to diffuse infiltrate of mast cells in upper dermis
• Stain: CD117, c-kit, leder stain, giemsa, toluidine blue, tryptase

Question 17

Stains for mastocytoma

Answer 17

Stain: CD117, c-kit, leder stain, giemsa, toluidine blue, tryptase

Question 18

Answer 18

Terminal ANAGEN with glycogenated ORS & keratinized IRS

Question 19

Answer 19

CATAGEN follicles are notable by their eosinophilic “glassy” membrane & lack of a hair shaft

*also hallmark is the presence of apoptotic cells

Question 20

Answer 20

TELOGEN follicle shows thick wrinkling bright eosinophilic keratin of IRS in the center

Question 21

Answer 21

ACNE VULGARIS

• Suppurative folliculitis and Perifollicular infiltrates
• Comedo - plug of corneocytes within a widened infundibulum

Question 22

Answer 22

ROSACEA - Erythemo-telangiectatic type

Question 23

Answer 23

ROSACEA - Erythemo-telangiectatic type

Question 24

Answer 24

Rosacea - Granulomatous type

• perifollicular infiltrates

Question 25

Scarring or non-scarring? ## Footnote *transverse specimen is best interpreted at the isthmus

Answer 25

Scarring Alopecia

Question 26

what are the features of scarring alopecia

Answer 26

* Loss of Sebaceous Glands * Presence of destructive inflammation or fibrosis around the follicles * Presence of compound follicles

Question 27

scarring or non-scarring?

Answer 27

NON-SCARRING ALOPECIA * Preserved Sebaceous Glands * Absence of destructive inflammation or fibrosis around the follicles

Question 28

Answer 28

ALOPECIA AREATA

Question 29

Answer 29

TRICHOTILLOMANIA ## Footnote Trichomalacia - distorted hair shaft

Question 30

Identify. What condition is this seen?

Answer 30

Hamburger sign: vertically oriented split in the hair shaft containing proteinaceous material and erythrocytes TRICHOTILLOMANIA

Question 31

What condition is this seen?

Answer 31

TRICHOTILLOMANIA

Question 32

Answer 32

ANDROGENETIC ALOPECIA

Question 33

Answer 33

LICHEN PLANOPILARIS

Question 34

Answer 34

Question 35

Question 36

Give examples of perivascular dermatitis without or minimal epidermal change

Answer 36

Question 37

Give examples of perivascular dermatitis without or minimal epidermal change consisting of LYMPHOHISTIOCYTIC infiltrates

Answer 37

* Erythema Annulare Centrifugum * Pigmented Purpuric Dermatosis * Polymorphous Light Eruption * Postinflammatory pigmentary alteration (PIPA) * Tumid Lupus * Vitiligo * Dermatophytosis * Erythrasma * Macular amyloidosis * Morbilliform viral exanthem * Morbilliform drug eruption * Tinea versicolor

Question 38

Give examples of perivascular dermatitis without or minimal epidermal change with MAST CELL INFILTRATES

Answer 38

* Urticaria pigmentoss * Telangietasia macularis eruptive perstans

Question 39

Give examples of perivascular dermatitis without or minimal epidermal change with EOSINOPHILIC infiltrates

Answer 39

* Urticaria * Urticarial hypersensitivity - (Arthropod bite assault or Drug)

Question 40

Classification of folliculitis

Answer 40

Question 41

Approach to alopecia

Answer 41