Top 30 Skin Diseases
Feb 12 2003
S Radhakrishna
Top 30 Skin Diseases
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Scaly Red Rashes (5) • Benign Growths (3)
Pigment Changes (2) • Premalignant
Growths (2)
Nodules (2)
• Malignant Growths
Purpura (1)
(3)
Blisters (4)
Systemic (3)
Scaly Red Rash 1: Seborrhea
Greasy yellow scaly plaques are
characteristically distributed in the scalp,
Tzone of face, hairy areas of face
(eyebrows, eyelashes, beard), behind the
ears, on the forehead, trunk, body folds,
and genitalia.Unknown etiology.
"cradle cap"
focal parakeratosis, moderate acanthosis, slight
spongiosis and a mild, mixed inflammatory infiltrate.
Scaly Red Rash 2: Psoriasis
Red or pink papule/plaque with silvery
or micaceous scaling. The fingernails
may show dystrophy, depressions known
as "pits" and subungual debis
presence of a thickened epidermis and
stratum corneum containing neutrophils and
neutophilic debris; no granular layer,
elongation of the rete ridges; T cell
involvement in etiology
Centrifugally spreading, reddish or pink
plaques or patches with slightly raised
advancing edge. Annular. Itchy rash
caused by fungus Tricophytum rubrum
in most cases.
Tinea corporis
Scaly Red Rash 3: Tinea
Tinea corporis
Tinea capitis
Tinea versicolor
Tinea capitis KOH prep on hair
“spaghetti and meatballs”
thick stratum
corneum
Tinea versicolor
Tinea unguium
Parakeratosis
Tinea pedis
PAS stain showing fungi
Scaly Red Rash 4: Eczema
Eczema is very itchy. There are variants
of eczema, the so-called "messy" rash,
for example, "irritant" eczema, atopic
eczema, and contact eczema, all of which
are characterized by rashes that are quite
itchy and appear "messy" because they
are often scratched.TH2 mediated DTH
Flexural distribution
Lichenification from scratching
crusting in the stratum corneum (making one
think of a "messy rash") and the "spongiosis"
or epidermal edema, as evidenced by the
relative pallor around the keratinocytes.
Scaly Red Rash 5: Scabies
Scabies (or infestation with the
Sarcopetes mite), especially when
untreated, can lead to a widespread
eczema rash with a few additional
distintive features such as heavy
involvement in the groin or skin folds
and, in particular, involvement of the
interdigital web spaces with crusting.
one finds a lot going on in the
stratum corneum. Here one
can see traces of the mite.
Pigment Changes 1: Vitiligo
With Fontana Masson stain, lesions of
long standing vitiligo (right hand panel)
show no melanocytes. In normal skin (left
panel) darkly stain melanocytes are
visible along the dermoepidermal
junction.
Pigment Changes 2: Melasma
large amount of melanin in the basal layer
HPV mediated. Here shown is common wart
Papules/Plaques 1: Warts
Flat wart
Genital wart
Aka condyloma
acuminatum
Plantar wart
The hallmarks of warts are hyperkeratosis, papillomatosis
(outward expansion of the spinous layer) and acanthosis.
The epidermis contains foci of vacuolated cells (koilocytes),
clumped keratohyaline granules, and vertical tiers of
parakeratotic cells (stratum corneum with retained nuclei).
Papules/Plaques 2: Molluscum
dome-shaped pink-brown papules with
secondary umbilication noted in mnay of the
well-developed lesions
ballooning-like changes in the keratinocytes as
they approach the granular layer. There are
intracellular inclusion bodies known as molluscum
bodies.
Papules/Plaques 3: Acne Vulgaris
Papules/Plaques 4: Urticaria (Hives)
There is little that appears wrong in this histology except for
the fact that there is a separation of the collagen bundles,
more so than one would usually see in normal skin. There is
also a sparse infiltrate in which an occasional lymphocyte
may be seen
Papules/Plaques 5: Erythema
Multiforme
The pathologic features of erythema multiforme include a perivascular,
lymphocytic infiltrate of variable intensity, vacuolization of the dermalepidermal junction, extravasation of red blood cells without vasculitis,
papillary dermal edema, and variable eosinophilic necrosis of the
epidermis.
Nodules 1: Erythema Nodosum
histologic findings associated with erythema nodosum are
largely localized to the deep dermis and the subcutaneous
tissue. There is an accumulaton of lymphocytes,
neutrophils, histiocytes, and giant cells accumulate in the
fibrous septae between fat lobules and perivascular
infiltration of lymphocytes in the dermis.
Nodules 2: Keloids
change in the diameter of the collagen bundles
and a kind of bluish background, the latter
indicating that there is some mucin there.
Purpura 1: Vasculitis
larger vessel is involved in an inflammatory porcess
vasculitis of the
superficial
vascular plexus.
One sees
extravation of red
blood cells,
indicating that
the vessels must
have been
damaged. There
is a lot of
neutrophilic
debris.
Blisters 1: Herpes
Note: these images are kind of weak, also,
not sure if they are only referring to HSV 1
or HSV 1 and HSV 2.
cells in the epidermis are undergoing degenerative changes. There is
acantholysis (epidermal cells falling apart) and enlarging of the nuclei. In
some specimens, one might be lucky enough to see the diagnostic mltinucleated giant cells
Blisters 2: Bullous Pemphigoid
sub-epidermal blister and an infiltrate with
plenty of eosinophils
Blisters 3: Pemphigus Vulgaris
INTRAEPIDERMAL split! (above
basal layer)
Mucosal involvement
Blisters 4: Acute Contact Dermatitis
Systemic 1: Lupus
discoid lupus. There is a
perivascular and
periappendageal lymphocytic
infiltrate that also tends to hug
the dermo-epidermal junction,
the latter type of infiltrate
being referred to as "lichenoid
Systemic 2: Scleroderma
The collagen bundles are thickened and homogenized.
Systemic 3: Drug Eruption
Benign Growths 1: Lentigo
two features here: the excess pigment in the basal layer and the
peculiar elongation of the epidermis itself, sometimes likened to a
"hockey stick".
LentiginesThese brown macules are sometimes
inappropriately referred to as "liver spots" by
lay people.
Benign Growths 2: Seborrheic
Keratosis
epidermal growth whose borders can almost be distinguished by a
pencil line drawing. The cells are banal and basophilic. There are often
"pseudo-horn cysts" or keratinaceous intra-epidermal inclusions.
Benign Growths 3: Nevi
Junctional Nevus
nests of melanocytes
occupy the junction
of the epidermis and
dermis
Compound Nevus
nests of melanocytes
occupy not only the
junction of the epidermis
and dermis, but are also
solidly in the dermis.
Dermal Nevus
nests of melanocytes are all
in the dermis.
(Dysplastic nevi are pre-melanomas)
Premalignant Growths 1: Dysplastic
Nevi
nevi are dysplastic. They are larger than most common nevi and
show a slight (minimal) variation in color and border.
(Aks are pre-squamous cell carcinoma)
Premalignant Growths 2: Actinic Keratosis
Actinic keratoses are single (<6 mm) or multiple discrete, dry,
rough, adherent scaly lesions which occur on the sun-exposed
skin of adults. Prolonged or repeated sun exposure leads to
cumulative UVB-damage to keratinocytes. Skin lesions have
adherent, disorganized, hyperkeratotic scale which is not
easily removed. Lesions are often easier to feel (they fill like
sandpaper) than to see. They are typically distributed on the
face, ears, neck, forearms and dorsa of hands.
maturation disarray in the epidermis and the cells
appear lsightly atypical
Malignant Growths 1: Basal Cell Carcinoma
Nodular bcc
Superficial bcc
Nodular bcc
Pigmented bcc
Basal cell carcinomas typically contain nests of basophilic cells
arising from the basilar portion of the epidermis and extending
into the dermis. The nests of basal cells show a distinct
perpindicular arrangement of the cells at the periphery of the
nests called palisading. The nests are also surrounded by a fibrous
stroma and retraction artefact is often observed at the edges of
many nest.
Malignant Growths 2: Squamous Cell Carcinoma
tumor islands
have irregularly
invaded the
dermis. There are
many atypical
cells
Melanomas are recognizable by their irregular and
indistinct boarders, multiple colors, asymmetry,
and varigate contours (raised and flat arease
within the same lesion). Particularly worrisome
colors are black, red, gray or blue
Malignant Growths 3: Melanoma
Large islands of atypical pigment-containing cells invade the
dermis irregularly
Melanoma arising from nevi