Psoriasis pathogenesis

HARP

• Hyperkeratosis – thickening of cornified layer
• Acanthosis – epidermal thickening (3-5 times normal)
• Rete ridge elongation (arrowheads)
• Parakeratosis – retained nuclei in stratum corneum

Other features:
Absent granular layer and infiltration of neutrophils and activated lymphocytes (from dermis to epidermis)
Nail changes (occur in 50% of patients)

STOP

• Subungual hyperkeratosis (proliferation under nail bed)
• Thickening
• Onycholysis (separation from the nail bed)
• Pitting, ridging

Sturge-Weber symptoms

STURGE

• Seizures
• Trigeminal port-wine stain
• Unilateral weakness (often opposite side to stain)
• Retardation (mental) in some patients
• Glaucoma
• Eye problems e.g. buphthalmos

the causes of hypopigmentation

(A PIGMENTED)

A: Autoimmine(vitiligo)
PI: Post Inflammatory.
G: Genetic(albinism).
M: Malignancy(malignant melanoma). E: Endocrine(hypopituitarism).
N: halo Naevus.
T: Trauma.
E: Endocrine.
D: Drugs(hydroxychloroquine)

causes of hyperpigmentation

(PIGMENTED):

PI: Post Inflammatory.
G: Genetic(freckles , lentigens and
xeroderma pigmentosum).
M: Malignancy and Melasma. E: Endocrine(cushing and addisson).
T: Trauma.
E: Endocrine.
D: Drugs(photosensitves)

Wound healing: factors delaying

DID NOT HEAL:


Drugs
Infection/ Icterus/ Ischemia
Diabetes
Nutrition
Oxygen (hypoxia)
Toxins
Hypothermia/ Hyperthermia
EtOH
Acidosis
Local anesthetics

Raynaud's phenomenon: causes

COLD HAND:


Cryoglobulins/ Cryofibrinogens
Obstruction/ Occupational
Lupus erythematosus, other connective tissue disease
Diabetes mellitus/ Drugs
Hematologic problems (polycythemia, leukemia, etc)
Arterial problems (atherosclerosis)
Neurologic problems (vascular tone)
Disease of unknown origin (idiopathic)

Psoriasis: pathophysiology

PSORIASIS


Pink Papules/ Plaques/ Pinpoint bleeding (Auspitz sign)/ Physical injury (Koebner phenomenon)/ Pain
Silver Scale/ Sharp margins
Onycholysis/ Oil spots
Rete Ridges with Regular elongation
Itching
Arthritis/ Abscess (Munro)
Stratum corneum with nuclei, neutrophils
Immunologic
Stratum granulosum absent/ Stratum Spinosum thickening

Malignant melanoma: 3 sites with poor prognosis

BANS

Back of Arm
Neck
Scalp

Generalized skin hyperpigmentation: causes

"SPARED"


Sunlight
Pregnancy
Addison's disease
Renal failure
Excess iron (haemochromatosis)
Drugs (eg busulphan)