CM: Scaling Disorders

Question 1

What is scale, nummular, pityriasis, and guttate?

Answer 1

scale = pieces of stratum corneum
nummular = coin-shaped
pityriasis = bran-like
guttate = shaped like drops

Question 2

What causes scaling?

Answer 2

abnormal keratinization: increased proliferation of basal keratinocytes, abnormal maturation, or increased retention of corneocytes

Question 3

What is parakeratosis?

Answer 3

nucleated stratum corneum cells - indicates incrased proliferation of basal keratinocytes and incomplete keratinization

Question 4

What causes psoriasis?

Answer 4

autoimmune w inappropriate activation of immune cells (dendritic and T cells) and cytokines that cause keratinocyte activation and proliferation

Question 5

What is seen on histology in psoriasis?

Answer 5

inflammatory cells in epidermis and dermis
accumulation of neutrophils in epidermis
increased mitosis of keratinocytes
thickening of epidermis = acanthosis
parakeratosis
absence or shrunken granular layer

Question 6

What parts of the body does psoriasis have a predilection for?

Answer 6

scalp, extensor limbs, elbows, knees, shins, sacral region, palms, soles, nails

Question 7

What are the different clinical patterns of psoriasis?

Answer 7

plaque type = classic, most common

guttate type, inverse (axilla and gluteal cleft), erythrodermic, pustular (often palms or soles)

Question 8

What are big diagnostic clues for psoriasis?

Answer 8

koebner phenomenon
nail involvement - pits, oil-drop changes, onycholysis
arthritis - often symmetric

Question 9

How long after primary inf does the secondary stage of syphilis appear?

Answer 9

6-8 wks

Question 10

What is seen on histology in the secondary stage of syph?

Answer 10

epidermal hyperkeratosis
dermis - perivascular infiltrate of monocytes, lymphocytes and *plasma cells
dilation and proliferation of capillaries
silver stain shows spirochetes

Question 11

What is the clinical manifestation of the secondary stage of syph?

Answer 11

brown-red macules or papules on trunk and extremities - frequently palms and soles
can also manifest as vesicles or pustules or mucous patches (condyloma lata) - mimics lots of stuff
can have diffuse hair loss, inc lateral 1/3 of eyebrow

Question 12

What is the histology of seborrheic dermatitis?

Answer 12

focal parakeratosis at edges of follicular ostia
often some spongiosis with modest neutrophilic infiltrate
psoriasiform dermatitis

Question 13

Which parts of the body does seborrheic dermatitis have a predilection for?

Answer 13

scalp, eyebrows, eyelids, nasolabial folds, ears, sternal area, axillae, sub mammary folds, umbilicus, groin, gluteal creases = areas with a lot of sebum

Question 14

What are the different clinical patterns of seborrheic dermatitis?

Answer 14

classic = greasy yellowish scale on face, dandruff of scalp
infantile - scalp!
sebopsoriasis - mixed features, esp on scalp
erythroderma
immunosuppressed pts - resistant to tx

Question 15

What is the cause of pityriasis rosa?

Answer 15

maybe HHV-6 or HHV-7 but unknown

Question 16

What is the histology of pityriasis rosa?

Answer 16

nonspecific
parakeratosis containing serum
focal spongiotic dermatitis pattern w superficial perivascular lymphocytic infiltrate

Question 17

What is the clinical manifestation of pityriasis rosa?

Answer 17

starts w herald patch on trunk followed by crops of smaller round to oval salmon-colored patches following lines of christmas tree pattern, peripherally attached thin scales, self limited

Question 18

What is the cause of pityriasis lichenoides?

Answer 18

T-cell lymphoproliferative disorder, trigger unclear

Question 19

What is the histology of pityriasis lichenoides?

Answer 19

epidermis w parakeratosis and spongiosis, keratinocyte necrosis, erythrocytes in epidermis
wedge shaped inflammatory infiltrate in dermis

Question 20

What is the clinical manifestation of pityriasis lichenoides?

Answer 20

acute = bright red edematous papules, may erode or ulcerate
chronic = red-brown lesion w scale, post inflammatory hyperpigmentation

Question 21

What is the cause of lichen planus?

Answer 21

T-cell lymphoproliferative disorder, trigger unclear

Question 22

What is the histology of lichen planus?

Answer 22

epidermis: hyperkeratosis w irregular acanthosis, focal hypergranulosis, civatte or colloid bodies (round or ovoid, eosinophilic deposits in lower epidermis or upper dermis)
dermis - band like lymphocytes along dermal epidermal jxn, pigment incontinence, loss of melanin from basal cells w accumulation of melanin in upper dermis

Question 23

What is the clinical manifestation of lichen planus?

Answer 23

flat topped, polygonal violaceous papules that can coalesce into plaques, Koebnerization
the P’s: purple, polygonal, pruritic*, papules
can have fine white lines = Wickham striae - wrists, pretibial area, mucous membranes
*oral lesions, nail involvement

Question 24

What is the cause of lichen simplex chronicus?

Answer 24

persistent rubbing or scratching results in contemporary hyperplasia

Question 25

What is the histology of lichen simplex chronicus?

Answer 25

hyperplasia of epidermis w hyperkeratosis, hypergranulosis, acanthosis, and elongated/irregular rete ridges, spongiosis

Question 26

What is the clinical manifestations of lichen simplex chronicus?

Answer 26

thickened and hyperpigmented plaque, skin lines easily visible, areas usually sharp and demarcated
pruritis is a prominent feature

Question 27

What are ichthyoses?

Answer 27

hereditary disorders characterized by abnormal maturation of skin resulting in abnormal (thick, fish-like) scaling
non specific histologies- all have compact hyperkeratosis and normal or thickened granular layer

Question 28

What are unique features of ichthyosis vulgaris?

Answer 28

decreased or absent granular layer

Question 29

What are unique features of epidermolytic hyperkeratosis?

Answer 29

hypergranulosis w giant keratohylain granules, keratinocyte lysis resulting in subcutaneous vacuolization and vesicles

Question 30

What is ichthyosis vulgaris?

Answer 30

AD caused by mutation in filaggrin - non-inflamed scaling, association w atopic dermatitis

Question 31

What is x-linked ichthyosis?

Answer 31

mutation in steroid sulfatase, neck almost always affected, palms, soles and face spared

Question 32

What is lamellar ichthyosis?

Answer 32

AR caused by mutations in transglutaminase 1, ABCA12
newborns have colloidion membrane, adults have thick plate-like scale that can be cosmetically disfiguring, not a lot of inflammation

Question 33

What is epidermolytic hyperkeratosis?

Answer 33

AR from mutations in Keratin 1 or 10

newborns have blisters and erosions, later replaced by extreme hyperkeratosis

Question 34

What lab tests might be necessary in scaling patients?

Answer 34

KOH scraping for any suspicion of fungus
RPR, FTS-ABS, HIV tests for syphilis
Hepatitis panel for lichen planus
pityriasis rosea - HHV-6 screening
biopsy
additional: genetic testing, imaging, CBC