Anatomy of skin, Lichen planus, Dermatitis, Koebner phenomenon, collagen defects and elastin defects have been mentioned in details with various images to help u in understanding it well.

1. - DR.AKIF A.B

2. Mnemonic:
COLLEGE – SCHOOL-BIRTH
First we are born—then we
Go to School…then we go to college
C = Corneum
o
L = Lucidum
l
e
G = Granulosum
e
School = Spinosum
Birth = Basale
OUTSIDE
INSIDE

4. Cells forms at base and then migrates upwards to form other layers of skin

6. As explained in previous question : Cells forms at base and then migrates
upwards to form other layers of skin and since Stratum corneum is the upmost layer ,
it forms at last and thus absent in premature babies

9. -Flat, Anucleate cells.
-Eosinophilic
- Hyperkeratosis : Increase in thickness
- Parakeratosis : Retention of nuclei in cells of stratum corneum.
- Dermatophytosis : Fungal infection in stratum corneum.
- Sarcoptes scabiei, causative organism of Scabies causes burrows in
stratum corneum .

12. Layer Cell type
Stratum corneum (horny layer) •Called corneocytes or squames.
•Dead, dried-out hard cells without
nuclei.
Stratum granulosum (granular layer) •Cells contain basophilic granules.
•Waxy material is secreted into the
intercellular spaces.
Stratum spinulosum (spinous, spiny
or prickle cell layer)
•Intercellular bridges
called desmosomes link the cells
together.
•The cells become increasingly flattened
as they move upward.
Stratum basale (basal layer) •Columnar (tall) regenerative cells.
•As the basal cell divides, a daughter cell
migrates upwards to replenish the layer
above.

13. -Translucent layer
- contains degenerated cells
- Present in palms & soles.
- Not present in skin all over body( + ONLY IN PALMS & SOLES)

14. - Granules +
Keratohyaline Lamellar
-Basophilic
- produces FILAGGRIN protein
Made of Keratin
Intermediate
filaments
Mutated in cases of
1) Ichthyosis Vulgaris
2) Atopic dermatitis
-ODLAND bodies
or Cementosomes
-Produces Lipid
which functions as
barrier of skin

15. -Fish Scale Disease.
- Caused due to mutation of FILLAGRIN protein in stratum granulosum
Filaggrin is a protein required for the binding of keratin fibres in epidermal cells,
to form an effective skin barrier.
- It helps maintain the skin pH, retain moisture in the stratum corneum, and
reduce trans-epidermal water loss (TEWL).
- Xerosis or dryness results from the reduced skin hydration associated with
defective filaggrin. Excessive scale results from the inability of the squamous
(skin cells) to remain hydrated as they move upward through the stratum corneum.
- Hyperkeratosis results from compensatory repair mechanisms increasing cell
proliferation.

18. - Reaction pattern of Skin.
Acute Sub-Acute Chronic
-Erythema
- Vesicle
Oozes
Crusts
-Erythema
- Scaling
-Lichenification
Thickening of skin
Hyperpigmentation
Exaggereted skin margins

19. - Reaction pattern of Skin.
Exogenous Endogenous
1) Allergic contact dermatitis
2) Irritant contact dermatitis
3) Phytodermatitis
4) Photodermatitis
1) Seborrhoeic dermatitis
2) Stasis Dermatitis
3) Atopic Dermatitis
4) Discoid eczema
5) Pityriasis alba
6) Pompholyx
7) Asteatotic Eczema

20. Spongiosis is mainly intercellular edema (abnormal accumulation of fluid) in
the epidermis, and is characteristic of eczematous dermatitis, manifested
clinically by intraepidermal vesicles (fluid-containing spaces), "juicy" papules,
and/or lichenification.

35. - Also known as Gravitational Eczema/ Chronic venous insufficiency

36. -Defect in skin barrier function making the skin more susceptible to irritation
by soap and other contact irritants, the weather, temperature and
non-specific triggers.
- Increased IgA response to allergen
Infantile Childhood Adult
-Extensor aspect
- 0-2yrs
- On face
Cheek
Scalp
-Flexural aspect
- 2yrs to puberty
- Papules
Excoriations
Eczemas
- Flexural aspect
- Puberty -Adult
- Lichenoid
Plaques

37. 1) Chronic / Chronically relapsing condition
2) Pruritis
3) Typical morphology & Distribution
4) Personal/ Family h/o atopy

44. The name refers to its appearance:
Pityriasis refers to its characteristic fine scale
Alba to its pale colour (hypopigmentation).
primarily affects children.

46. -Decrease surface skin lipids
- also known as ECZEMA CRACQUALE

49. -Prickle cell layer
- Spines + ( Acantha) : known as desmosomes
- Acantholysis : Rupture of Desmosomes
Connects Keratin
Intermediate filaments
Loss of adhesion between epidermal cells
leading to separation of cells and this cells
are now known as Acantholytic cell/Tczank cell

52. PRIMARY
PEMPHIGUS
SECONDARY
ACANTHOLYSIS

53. -Single layer
- Columnar cell with central nucleus
- Lichen Planus : Lymphocyte infiltrates basal layer leading to basal cell degeneration

74. -Present in all layers of epidermis.
- forms 80% of all cells in epidermis
-Ectodermal in origin

75. -Dendritic type of cell.
-Function : Pigment production
- Origin : Neural Crest
-Location : Stratum basale
- for every 1 melanocyte, there are 10 keratinocytes
- also present in Iris, Leptomeninges & Inner ear
- Vogt Koyanagi Harada Syndrome : Defect of melanocyte
-1 melanocye gives melanin to 36 keartinocytes.

76. VOGT KOYANAGI HARADA
SYNDROME
-It involves all places where melanin is present like :
1) skin = Poliosis ( White patches in hair and skin due to loss of melanocyte )
2) Iris = Uveitis
3) Leptomeninges
4) Inner ear = Sensorineural deafness

77. -Type of macrophage.
-Origin : Bone marrow
-Location : stratum spinosum
-Dendritic cell
-Markers : CD1a
S100
CD-207 : Most specific
Used to diagnose Langerhan
cell histiocytosis

78. - Granules in Langerhan cell : BIRBECK granules (Electron microscope)
BIRBECK granules

80. - Horse shoe arrangement of nuclei.

81. -Bilobed nucleus
-Mechanoreceptors
-Location : Stratum basale
-Markers : Cytokeratin-20
- forms synapse with nerve

83. -Portion of epidermis which enters dermis.

84. - Portion of dermis which enters epidermis.

85. FIBRES
Collagen
elastic
APPENDAGES
Sweat Glands
Sebaceous Glands
Hairs
BLOOD VESSELS
NERVES

86. & Skin

89. COLLAGEN DEFECT DISEASE
1) Type-1 Collagen Osteogenesis Imperfecta
2) Type-2 Collagen Relapsing Polychondritis
3) Type-3 Collagen Ehlers Danlos syndrome
4) Type 7 collagen Epidermolysis bullosa

90. - DR.AKIF A.B
1) MARFAN SYNDROME
2) CUTIS LAXA
3) PSEUDOXANTHOMA ELASTICUM

91. - Defect in fibriilin component of elastin fibres.
- Marfan syndrome is a connective tissue disorder that mainly affects the
1) bones and joints (skeletal system)
2) heart and blood vessels (cardiovascular system)
3) the eyes.

92. The main characteristic features of the syndrome include:
1) tall and thin stature with long extremities (arms, legs, fingers and toes
disproportionately long in relation to rest of the body)
2) Eye problems where one or both lenses of the eye may dislocate,
3) heart and blood vessel problems that may result in heart murmurs, irregular
heartbeat, or in severe cases aortic aneurysm (potentially fatal heart condition).

94. Michael Phelps : Top swimmer is known to have few symptoms of
Marfan Sx.

95. -Recoil of skin after pinching will be slow.
- characterised by loosely hanging skin that lacks any elasticity.

96. -Group of connective tissue disorders that affects the elastic tissue of the skin,
blood vessels, and the eyes.
- Calcium deposits over defective elastin fibres.
- Collagen and ground substance is normal.
- Plucked Chicken appearance of Neck.
-Angioid streaks in retina.

97. Plucked Chicken appearance

98. Plucked Chicken appearance

99. Plucked Chicken appearance

100. 1) Pseudoxanthoma elasticum
2) SLE
3) Ehlers danlos Syndrome.