PERIVASCULAR AND DIFFUSE DERMATITIS, NON-INFECTIOUS FOLLICULITIS AND PERIFOLLICULITIS Flashcards
URTICARIA
- Sparse perivascular & interstitial infiltrate (LYMPHOCYTES, NEUTROPHILS,EOSINOPHILS)
- +/- Dermal edema
- Almost normal looking skin biopsy
PIGMENTED PURPURIC DERMATOSIS
- Perivascular infiltrate composed of lymphocytes
- Extravasated erythrocytes
- Siderophages
Variable mild epidermal changes: Spongiosis, Lymphocyte exocytosis
What stain can be requested to highlight siderophages? What condition can this be seen?
Perl’s Stain
Pigmented Purpuric Dermatosis
POLYMORPHOUS LIGHT ERUPTION
- Superficial and Deep
- Lymphocyte predominant
- Marked papillary edema
ARTHROPOD BITE HYPERSENSITIVITY
ERYTHEMA ANNULARE CENTRIFUGUM
- Perivascular lymphohistiocytic infiltrate
POST-INFLAMMATORY PIGMENT ALTERATION
- Normal looking epidermis
- Mild Perivascular lymphohistiocytic infiltrate
- Numerous Melanophages present in the superficial dermis
VITILIGO
- Absence of melanocytes in the dermo-epidermal junction
- Normal looking epidermis
- Mild Perivascular lymphohistiocytic infiltrate
Normal melanocyte to keratinocyte ratio
1:4-1:10
Stains to highlight melanocyte
S100, SOX HMB-45, MART-1, Melan-A, MITF
Stains to highlight melanin
Fontana-Masson, Silver nitrate
TUMID LUPUS
- Normal looking epidermis
- Dense lymphohistiocytic infiltrate surrounding adnexa
- Superficial and Deep Perivascular lymphohistiocytic infiltrate
- Mucin highlighled by Alcian Blue
SWEET’S SYNDROME
No fibrinoid degeneration or necrosis
PYODERMA GANGRENOSUM
- Fibrinoid deposition of blood vessels and Endothelial swelling
- Follicular or perifollicular inflammation with micro-abscess formation
MASTOCYTOSIS – URTICARIA PIGMENTOSA
- Loosely scattered or grouped mast cells in dermis
- Basal hyperpigmentation
MASTOCYTOSIS - MASTOCYTOMA
- Nodular to diffuse infiltrate of mast cells in upper dermis
- Stain: CD117, c-kit, leder stain, giemsa, toluidine blue, tryptase
Stains for mastocytoma
Stain: CD117, c-kit, leder stain, giemsa, toluidine blue, tryptase
Terminal ANAGEN with glycogenated ORS & keratinized IRS
CATAGEN follicles are notable by their eosinophilic “glassy” membrane & lack of a hair shaft
TELOGEN follicle shows thick wrinkling bright eosinophilic keratin of IRS in the center
ACNE VULGARIS
- Suppurative folliculitis and Perifollicular infiltrates
- Comedo - plug of corneocytes within a widened infundibulum
ROSACEA - Erythemo-telangiectatic type
ROSACEA - Erythemo-telangiectatic type
Rosacea - Granulomatous type