Top 30 Skin Diseases

1
Top 30 Skin Diseases

• Feb 12 2003
• S Radhakrishna

2
Top 30 Skin Diseases

• Scaly Red Rashes (5)
• Pigment Changes (2)
• Nodules (2)
• Purpura (1)
• Blisters (4)
• Systemic (3)

• Benign Growths (3)
• Premalignant Growths (2)
• Malignant Growths (3)

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.
focal parakeratosis, moderate acanthosis, slight
spongiosis and a mild, mixed inflammatory
infiltrate.
"cradle cap"
4
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
5
Scaly Red Rash 3 Tinea
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
Tinea corporis
Tinea capitis KOH prep on hair spaghetti and
meatballs
Tinea capitis
Tinea versicolor
thick stratum corneum
Tinea versicolor
Tinea unguium
Parakeratosis
PAS stain showing fungi
Tinea pedis
6
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.
7
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.
8
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.
9
Pigment Changes 2 Melasma
large amount of melanin in the basal layer
10
Papules/Plaques 1 Warts
HPV mediated. Here shown is common wart
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).
11
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.
12
Papules/Plaques 3 Acne Vulgaris
13
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
14
Papules/Plaques 5 Erythema Multiforme
The pathologic features of erythema multiforme
include a perivascular, lymphocytic infiltrate of
variable intensity, vacuolization of the
dermal-epidermal junction, extravasation of red
blood cells without vasculitis, papillary dermal
edema, and variable eosinophilic necrosis of the
epidermis.
15
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.
16
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.
17
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.
18
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 mlti-nucleated giant
cells
19
Blisters 2 Bullous Pemphigoid
sub-epidermal blister and an infiltrate with
plenty of eosinophils
20
Blisters 3 Pemphigus Vulgaris
INTRAEPIDERMAL split! (above basal layer)
Mucosal involvement
21
Blisters 4 Acute Contact Dermatitis
22
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
23
Systemic 2 Scleroderma
The collagen bundles are thickened and
homogenized.
24
Systemic 3 Drug Eruption
25
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.
26
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.
27
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.
28
Premalignant Growths 1 Dysplastic Nevi
(Dysplastic nevi are pre-melanomas)
nevi are dysplastic. They are larger than most
common nevi and show a slight (minimal) variation
in color and border.
29
Premalignant Growths 2 Actinic Keratosis
(Aks are pre-squamous cell carcinoma)
Actinic keratoses are single (lt6 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
30
Malignant Growths 1 Basal Cell Carcinoma
Nodular 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.
Superficial bcc
Nodular bcc
Pigmented bcc
31
Malignant Growths 2 Squamous Cell Carcinoma
tumor islands have irregularly invaded the
dermis. There are many atypical cells
32
Malignant Growths 3 Melanoma
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
Large islands of atypical pigment-containing
cells invade the dermis irregularly
Melanoma arising from nevi