2. PITYRIASIS
• Any of several skin diseases marked by the
formation and desquamation of fine scales
3. PITYRIASIS ROSEA
• Self limited dermatitis lasting from 4-7 weeks
• Predominantly occur in adolscents and young
adults
• May be asymptomatic or pruritic
• Etiology unknown,viral origin has been
suggested
4. • Characterized by development of self limiting
eruption
• Eruption preceded with large scaly annular
plaque known as Herald patch or mother
patch
• It is a raised Plaque
• Within a week after heralad patch formation
• Numerous oval shaped uniform papules and
macules with peripheral collateral scales
appear abruptly(1-2cm of size)
7. • On the back of trunk ,lesion show a fur tree or
christmas tree like pattern
8. • Hanging curtain sign positive
• When individual lesion is stretched along the
long axis ,the scales tend to fold across the
lines of stretch
• Histological features
• Focal parakeratosis
• Mild acanthosis
• Spongiosis
• Exocytosis
• Perivascular dermal infilitration with
lymphocytes
9. DIAGNOSIS
• Usually easily diagnosed by its morphology
and distribution
• Can also occur as a manifestation of
• 1.Secondary syphilis
• 2.Drug reaction
• 3.Internal malignancy(stomach)
10. TREATMENT
• Since self limiting ,no active treatment
required
• Application of bland oils and avoidance of
soap may relieve itching
• Severe itching -Oral antihistamines
,antipruritic lotions
11. PITYRIASIS LICHENOIDES
• Divided into two
• 1.Pityrisis lichenoides chronica
• 2.Pityriasis lichenoides et varioliformis acuta
(PLEVA) or Muscha-Habermann disease
• They are two types of Parapsoriasis,other than
parapsoriasis en plaque
12. PARAPSORIASIS
• Includes a group of
chronic,asymptomatic,maculopapular scaly
eruptions of slow evolution
• Resistant to treatment
13. 1.PITYRISIS LICHENOIDES CHRONICA
• Common type of parapsoriasis
• Seen in children
• Consists of discrete,scaly,erythematous
• 1.Macules
• 2.Papules
• Papule shows a single layer of brownish scale
• Removel of scale spoty hypopigmented
oval macule
16. • Difference from psoriasis
• 1.When one tries to remove the brownish
scale,it comes out as a wholeand not in layers
• 2.Auspitz sign absent
17. Auspitz sign
• When scales are scrapped off completely in
psoriasis patient ,the basement membrane is
exposed and is seen as moist red surface
• Through which dilated capillaries are seen as
red spots
• On further scrapping these capillaries at tips
of elongated papillae are torn leading to
multiple bleeding points(auspitz sign)
18. TREATMENT
• No active treatment indicated
• Bland emollient application beneficial
• Oral Tetracycline and PUVA therapy has been
reported effective
19. 2.Pityriasis lichenoides et
varioliformis acuta (PLEVA)
• Abrupt onset
• Consists of erythematous
macules,papules,necrotic lesions,and few
vesicles
• Eythematous papules tend to
• 1.Crusting
• 2.Necrosis
• 3.Hemorrhage
21. Histological features
• Dense lymphocytic perivascular infilitration in
supficial dermis
• Erythrocytes trapped within epidermis
• Lesions heal leaving depressed varioliform (resembling
smallpox) scar
• New lesions may erupt and disease can be chronic or
subacute
