Download MBBS Dermatology PPT 17 Lichen Planus Pityriasis Rosea Lecture Notes

Download MBBS (Bachelor of Medicine, Bachelor of Surgery) Dermatology PPT 17 Lichen Planus Pityriasis Rosea Lecture Notes


Lichen Planus

&

Pityriasis Rosea

Lichen Planus
Leichen ? tree moss ; planus ? flat
Coined by Sir William James Erasmus Wilson in 1869

Idiopathic, inflammatory disorder affecting skin ,

mucous memb , nails & hair.

Chronic course with relapses and remissions

Affects 0.5% of the population
Age group affected: 30 ? 60 years
rare in children

ETIOLOGY :

1. Idiopathic
2. Familial associations: HLAA3, A5, B7, DR1 and

DRB*0101.

3. Drugs causing LP like eruptions ? gold salts, beta blockers,

antimalarials, thiazides, furosemide, spironolactone, penicil amine

4. Dental amalgams
5. Infections ? HCV
6. Betel leaf, areca nut use in South East Asia - oral LP
PATHOGENESIS

The exact pathomechanisms are unclear
Autoimmunity is clearly suggested to be central in

pathogenesis in LP

1. LP ? specific antigen recognition
2. Cytotoxic Lymphocyte Activation
3. Keratinocyte Apoptosis

CLINICAL FEATURES

firm, shiny, polygonal, 1?3 mm diameter papules, red to

violet

6 P's --- purple, pruritic, polygonal, plane topped,

papules, plaques

Pruritus: mild irritation, to continuous severe itching

interfering with sleep

distribution: isolated/grouped, linear/annular
resolved lesions: greyish brown due to
deposition of melanin in the superficial dermis.


Sites : volar aspect of the wrists, lumbar region,

ankles, shins, scalp, palms, soles.

Oral and genital mucosa


- WICKHAM'S STRIAE :on

BROCQ'S

close inspection a trace of

PHENOMENON:

thin white lines seen on

Subepidermal

the surface of the lesions

hemorrhage

following scraping

of a classical LP

lesion

KOEBNER'S PHENOMENON

Development of

lesions in

previously normal

skin that has been

subjected to trauma


HISTOPATHOLOGY


TYPES OF LP

MORPHOLOGY

SITE

SPECIAL

HYPERTROPHIC

SKIN

ACTINIC

ATROPHIC

MUCOSAL

LP

(ORAL, GENITAL)

PEMPHIGOIDES

GUTTATE( ERUPTIVE)

PALMOPLANTAR

LP PIGMENTOSUS

ANNULAR

NAIL

LINEAR

SCALP

VESICULOBULLOUS

INVERSE

FOLLICULAR
ULCERATIVE/EROSIVE

HYPERTROPHIC LP

Hypertrophic or warty

lesions

Lower limbs, especially

around the ankles

Severely itchy
Must be distinguished

from lichen simplex

chronicus and lichen

amyloidosis


GUTTATE LP

Lesions are widely

scattered, discrete, size

(1?2 mm)

Differentiate from

guttate psoriasis

ANNULAR LP

very narrow rim of

activity with a

depressed, slightly

atrophic centre

characteristically found

on the penis


BULLOUS LP

blisters arise only on or

near the lesions of LP

short duration
HPE - severe liquefaction

degeneration of the basal

cell layer. Subepidermal

bulla with typical changes

of LP

direct and indirect

immunofluorescence

negative.

FOLLICULAR LP

Follicular lesions
Scalp
Intensely itchy
scarring alopecia


ACTINIC LP

Lichen planus

subtropicus ?

dark skinned, tropical

countries

welldefined

annular/discoid patches,

with a deeply

hyperpigmented centre &

surrounded by a striking

hypopigmented zone

Sunexposure :central to

the pathogenesis

LICHEN PLANUS PIGMENTOSUS

India, Middle East
macular

hyperpigmentation:

slate grey to

brownish black

face, neck and

upper limbs


LICHEN PLANUS PEMPHIGOIDES

acute and generalized
large bullae on both involved

and uninvolved skin.

HPE: subepidermal bulla

without evidence of LP

Direct IF: linear deposition of

IgG, C3 along basement

membrane zone in

perilesional skin

Immunoelectron

microscopy: deposition of

IgG,C3 in the base of the

bulla (unlike BP- roof )

LICHEN PLANUS: PALMS, SOLES

lesions are firm, rough

with a yellowish hue

broadly sheeted or

punctate

diagnosis is very

difficult; syphilis,

psoriasis, callosities

and warts must be

excluded
MUCOSAL LESIONS

Seen in 30?70% cases; may be isolated
Sites:

buccal mucosa,
tongue (most often involved)
genitalia- the penile shaft, glans penis, prepuce,

scrotum, vulva

perianal



Patterns Of Mucosal Involvement

? Reticulate ? most common
? Atrophic
? Hypertrophic
? Erosive/Ulcerative
? Plaque-like
? Papular
? Bullous




ORAL LP

Reticulate

pattern(M/C)

White streaks, often

forming a lacework.

inner surface of the

cheeks, gum

margins, lips.

Associated oral

candidiasis


VULVAL LP

welldemarcated

erosions/erythematous areas at

the vaginal introitus

hyperkeratotic border of lesions;

Wickham's striae in the

surrounding skin

vaginal inflammation
pain/burning, scarring/loss of

normal architecture

involvement of other mucosa

NAIL INVOLVEMENT

10% cases. Fingernails > toenails
initially 2/3 fingernails, subsequently remaining

digits.

Exaggerated longitudinal lines, linear depressions
Adhesion between the epidermis of the dorsal

nail fold and the nail bed: pterygium unguis

complete shedding


Exaggerated

Pterygium unguis

longitudinal lines

PROGNOSIS / COMPLICATIONS

Lesions resolve with pigmentation that may last for

many months

Recurrent episodes

Oral & hypertrophic lesions may be premalignant

Scarring alopecia
TREATMENT of LP

:

TOPICAL

PHOTOTHERAPY

SYSTEMIC

TCS

PUVA

STEROIDS

IMMUNOMODULATORS

RETINOIDS

TRETINOIN

STEROID SPARING

(ORAL LESION)

DRUGS

LIDOCAINE(ORAL

TETRACYCLINES

LESION)
VIT.D ANALOGUES

DAPSONE

METRONIDAZOLE

GRISEOFULVIN
THALIDOMIDE
BIOLOGICALS

TREATMENT LADDER:

CUTANEOUS

First line
Limited: very potent corticosteroids topical (eg.clobetasol

propionate ointment 0.05%);

Widespread: systemic prednisolone 0.5?1 mg/kg per day

until improvement

Second line
Prednisolone 0.5?1 mg/kg per day until improvement
Acitretin 30 mg per day for 8 weeks
PUVA /UVB: two to three times a week ? systemic

retinoids
TREATMENT LADDER: ORAL

First line
Symptomatic : very potent corticosteroids
Soluble prednisolone tablets, 5 mg in 15 mL water, mouthwash tds or

betamethasone soluble tablets 0.5 mg

Severe erosive LP: prednisolone 0.5?1 mg/kg per day
Second line
Papular ,plaquelike white forms no erosions: topical retinoids
Resistant to topicals: prednisolone 0.5?1 mg/kg
Third line
Steroid dependent/resistant erosive LP: Azathiprine, MMF, Mtx,

Cyclosporin A

TREATMENT LADDER: NAILS

< four nails
superpotent corticosteroids
Severe nail involvement :
monthly intralesional injection of triamcinolone acetonide (0.5

?10 mg/mL) in the periungual sites.

oral prednisolone (0.5?1 mg/kg/day)


LICHEN NITIDUS

pinpoint to pinheadsized

papules,

flesh coloured, with a flat,

shiny surface. Remain

discrete

asymptomatic
forearms, penis, abdomen,

chest, buttocks.

selflimiting, no treatment

intense, circumscribed,

infiltrate of lymphocytes,

histiocytes & few Langhans

cells situated immediately

below a flattened epidermis.

The rete ridges at the margin

of the infiltrate are elongated

to encircle it

liquefaction degeneration of

the basal cell layer.
PITYRIASIS ROSEA

Pityriasis ? scales ; Rosea ? pink ( Gilbert )
Acute , self-limiting disease , probably

infective in origin.

Children & young adults with a slight female

preponderence.

Minimal symptoms - pruritus


ETIOLOGY:

1. Viral : HHV 7 ; HHV 6 ? reactivation
2. Drugs : Metals ( Ar, Bi, Au)
Lithium
Methopromazine
Metronidazole
Barbiturates
Clonidine
Captopril etc.

CLINICAL FEATURES

HERALD PATCH
primary plaque/mother

patch.
Sharply defined

erythematous annular

plaque with a peripheral

col arette of scales.
M/C Site ? thigh,upper

arm,trunk or neck


Within 5-15 days
Generalised eruption

? discrete oval

lesions similar to the

herald patch but

smaller in size

Upper chest & back ? Christmas /Inverted Fir

tree pattern.

Face,scalp ? children
Palms ? rare, scaly red plaques / diffuse

redness / /small vesicles.

Oral ? ill defined red patches


Atypical / Morphological Variants:

papules / vesicles / papulovesicular
urticarial
erythema multiforme like
pustular
purpuric
lichenoid
exfoliative dermatitis


Epidermis ? patchy parakeratosis, spongiosis.
Dermis (upper) ? edema , mononuclear cel infiltrate ( exocytosis into

epidermis forming subcorneal pustules.

TREATMENT :

Acyclovir ( 800mg 5 times a day x 1 week)
Erythromycin (500mg qid x 2 weeks- adult

40mg/kg div.doses ? child)

Oral antihistamines
Topical steroids- mid potent
Topical antipruritic lotions
UVB.
THANKYOU

This post was last modified on 07 April 2022