Lichen Planus & Lichenoid Reactions

Question 1

At what age does Lichen Planus usually occur?

Answer 1

Between 20-50 years.

Question 2

How are the lesions in Lichen Planus described?

Answer 2

Polygonal flat topped violaceous papules.

They often cluster and bear a superficial fine white lacy reticulate pattern

This is known as Wickham’s Striae

Question 3

What areas of the body are most likely to be affected by lichen planus?

Answer 3

• Wrists
• Lower back
• Shins
• Ankles
• Mucous membranes
• Nails
• Scalp

Question 4

Lichen Planus can affect the Vulva.

How does this usually initially start to present?

Answer 4

Dyspareunia or pruritus

(They can also affect the underlying structure/architecture)

Question 5

How does Vulvar Lichen Planus differ from Lichen Sclerosus?

Answer 5

It doesn’t have the white pallor or purpura of Lichen Sclerosus

Question 6

When Lichen Planus affects the epithelium of the scalp, what is it known as?

Answer 6

Lichen Plano Pilaris (LPP)

Question 7

Does LP display the Koebner Phenomenon?

Answer 7

Yes

Question 8

What is the most common complaint when lichen planus erupts?

Answer 8

Itchiness

Question 9

What is the other main complaint with Lichen Planus when the active lesions start to settle?

Answer 9

Post Inflammatory hyperpigmentation

Question 10

What should you also consider if you notice that someone has Lichen Planus?

Answer 10

Consider examining genitals

(Vulvar Lichen Planus)

Question 11

If someone has alopecia due to lichen planus, what do you notice?

Answer 11

There will be peripilar scaling and erythema under the dermatoscopy.

Question 12

What is this?

Answer 12

Oral Lichen Planus

(Note Wickham’s Striae)

Question 13

What are the most common drugs to cause a lichenoid eruption?

Answer 13

• Anticonvulstants
• NSAIDs
• Diuretics
• Penicillamine

Question 14

Although most causes of Lichen Planus and Lichenoid Eruptions are idiopathic, what condition has been associated with it?

Answer 14

Hepatitis B & C

Question 15

What features point towards a lichenoid drug reaction vs lichen planus?

Answer 15

• Absence of Wickham’s Striae
• Extensive rash across the trunk, limbs.
• Nail and mucous membrane involvement is uncommon.

Question 16

If a lichenoid drug reaction occurs,

How quickly does it occur after starting the drug?

Are the quick or slow to resolve?

Answer 16

• 10 days to 2 months of commencing a drug therapy
• They are slow to resolve.

Question 17

Oral lichenoid eruptions have been related to [BLANK]?

Answer 17

Amalgam fillings

Question 18

80% of cases of idiopathic lichen planus will resolve in [BLANK]?

Answer 18

9-15 months

Question 19

If someone has oral lichen planus, what are they more prone to getting?

Answer 19

SCC form the oral areas of lichen planus

(Advise on reducing alcohol and smoking)

Question 20

Name some other types of lichen planus?

Answer 20

• Acitinic Lichen Planus
• Annular Lichen Planus
• Atrophic Lichen Planus
• Ashy Dermatosis
• Hypertrophic Lichen Planus
• Bullous Lichen Planus
• Lichen Planus Pemphigoides
• Linear LP

Question 21

What is this?

Where is it usually found on the body?

Answer 21

Hypertrophic Lichen Planus

• Usually on the lower legs and shins.
• Treatment: Potent topical steroids under occlusion for a few months followed by regular calcineurin inhibitors.
• Differential: Lichen Simplex Chronicus

Question 22

What is this?

Who usually gets it?

What is its differential?

Answer 22

Acitinic Lichen Planus

Minaly Type 5 skin from the Middle East

Differential Diagnosis: Melasma

Question 23

What is this?

Who usually gets it?

How is it treated?

Answer 23

Ashy Dermatosis

• Usually Skin types 3-5.
• Difficult to treat - Consider Potent steroids if biopsy shows inflammation.

Question 24

What is this an example of?

Answer 24

Linear Lichen Planus

It occurs spontaneously over Blashko’s lines.

Question 25

What is this?

Answer 25

Annular Lichen Planus

Rare

Usually occurs with classical Lichen Planus

More commonly seen in men in genitalia or intertriginous areas.

Question 26

What is the management strategy in lichen planus?

Answer 26

1. Check for hepatitis B &C if extensive disease
2. Check scalp, nails, mucous membranes and genitalia
3. Topical
   
   • Potent & Super Potent Steroids - good for most
   • Topical calcineurin inhibitors can also be tried.
4. Intralesional Steroids - used for nail, scalp & localised treatment
5. Systemic steroids - for widespread disease
6. Phototherapy - narrowband UVB as TLO-1
   
   • NOTE: PIH can be exacerbated by narrowband UVB
7. Other oral therapies
   
   • Cyclosporine, Azathioprine, Immunosuppresives can be used in recalcitrant cases.
   • Lichen planopilaris may respond to Hydroxychloroquine and Acitretin.
   • Tranexamic acid for PIH - treat for 6 months duration.

Question 27

How do you treat oral lichen planus?

Answer 27

Topical steroid in Orabase

(eg 0.1% triamcinolone in an adherent base)

OR

Steroid gargles (5mg soluble Prednisolone tablets) 4 times daily

OR IN RESISTANT CASES

Ciclopsorine mouthwash (100mg/ml rinse).

AND

Benzydamine Hydrochloride oral rinse for pain relief.