Additional conditions

Question 1

What is Pityriasis rosea ?

Answer 1

• It is an acute viral rash which lasts about 6–12 weeks.
• It is characterised by a herald patch followed by similar, smaller oval red patches that are located mainly on the chest and back.

Question 2

Who is most commonly affected by pityriasis rosea?

Answer 2

Teenagers & young adults

Question 3

Many patients with pityriasis rosea have no prodrome, but in a small number of patients what may they give a history of having ?

Answer 3

A history of recent upper respiratory viral infection (cough, cold, sore throat or similar).

Question 4

What are the clinical features of pityriasis rosea ?

Answer 4

• Solitary lesion ‘Herald patch’ appears 2-4days before onset of rash
• Herald patch = an oval pink or red plaque which is scaly on its inside edge
• Secondary rash occurs = multiple smaller oval scaly (on there inside edge) patches/plaques.
• Christmas tree effect following the ribs

Question 5

What part of the body does pityriasis rosea mainly affect?

Answer 5

Back & chest.

Question 6

What is shown in this pic ?

Answer 6

Herald patch - pityriasis rosea

Question 7

What is shown in this pic ?

Answer 7

They secondary rash in pityriasis rosea

Question 8

How is pityriasis rosea diagnosed ?

Answer 8

Clinically

Question 9

What is the treatment of pityriasis rosea?

Answer 9

Self-limiting so no treatment needed.

If itch consider giving 1 or more of the following:

1. sedating oral antihistamine (for example chlorphenamine
2. An emollient
3. A midly-moderately potent TCS

Question 10

What is lichen planus ?

Answer 10

It is a chronic inflammatory skin condition affecting the skin and mucosal surfaces. There are several clinical types of lichen planus that share similar features on histopathology.

• Cutaneous lichen planus
• Mucosal lichen planus
• Lichen planus of the nails
• Lichenoid drug eruption

Question 11

What parts of the body does cutaneous lichen planus tend to affect?

Answer 11

Location can be anywhere, but most often front of the wrists, lower back, and ankles.

Question 12

What are the clinical features of lichen planus ?

Answer 12

• Violaceous (pink/ purple) Papules & polygonal (many angled) plaques that are shiny, flat-topped, firm & have fine white lines crossed across them (Wickhams striae)
• Lesions are itensley itchy
• Plaques can be hypertrophic
• Koebner phenomenon may be seen (new skin lesions appearing at the site of trauma)
• Oral involvement common (50% of cases) - typically a white-laced pattern on the buccal mucosa
• Nail involvement - thinning of the nail plate & longitudinal ridging seen

Question 13

What is shown in this pic ?

Answer 13

Oral involvement of lichen planus

Question 14

What is shown in this pic ?

Answer 14

Nail features seen in lichen planus

Question 15

Describe what a lichenoid drug eruption is

Answer 15

This refers to a lichen planus-like rash caused by medication

Question 16

List the common drugs which cause lichenoid drug eruptions

Answer 16

• Gold
• Quinine e.g. hydroxyquinine
• Thiazides
• Furosemide
• B-blockers
• Catopril - ACEi

Question 17

How can lichenoid drug eruptions be distinguished from regular lichen planus ?

Answer 17

• Rash is usually extensive and distirbuted symmetrically over the trunk & limbs
• Wickham striae are usually absent
• Nail and mucous membrane (e.g., mouth) involvement is uncommon
• History of starting a new drug in the past year

Question 18

How is the diagnosis of lichen planus or a lichenoid drug eruption confirmed ?

Answer 18

Skin biopsy

Question 19

What are the characterisitic microscopic features of lichen planus ?

Answer 19

• Hyperkeratosis
• Thickened granular layer
• Jagged (saw-tooth) baseline of epidermis
• A dense band of lymphocytes and histiocytes at the DEJ.

Question 20

What is the treatment of lichen planus ?

Answer 20

Local treatments for the symptomatic cutaneous or mucosal disease are:

• topical steroids are the mainstay of treatment
• benzydamine mouthwash or spray is recommended for oral lichen planus

Widespread/severe lichen planus tx = Oral steroids (prednisolone) + one of the following:

• Acitretin
• Hydroxychloroquine
• Methotrexate
• Azathioprine
• Mycophenolate mofetil
• Phototherapy

Question 21

What is vitiligo ?

Answer 21

It is an acquired depigmenting disorder of the skin, in which pigment cells (melanocytes) are lost. It presents with well-defined milky-white patches of skin (leukoderma).

Question 22

Who in particular can vitiligo be a problem for ?

Answer 22

Black people

Question 23

What are the clinical features of vitiligo?

Answer 23

• Well-demarcated patches of white (depigmented) skin
• The peripheries tend to be most affected
• Trauma may precipitate new lesions (Koebner phenomenon)
• Without treatment, individual lesions usually enlarge over time and patches may merge to form extensive geographical patterns.

Question 24

What conditions is vitiligo associated with ?

Answer 24

• T1DM
• Addison’s disease
• Autoimmune thyroid disorders
• Pernicious anaemia
• Alopecia areata

Question 25

How is vitiligo diagnosed ?

Answer 25

Clinically

Question 26

What is the treatment of vitiligo ?

Answer 26

* Sunblock for affected areas of skin * Camouflage make-up * Topical corticosteroids may reverse the changes if applied early There may also be a role for topical tacrolimus and phototherapy, although caution needs to be exercised with light-skinned patients

Question 27

What is shown in this pic ?

Answer 27

Vitiligo

Question 28

What clinical feature is shown here ?

Answer 28

Beau's line - caused by transient arrest in nail growth, which occurs during acute stress/illness

Question 29

What is shown here ?

Answer 29

Subungual haemorrhage: * Presents as a discoloured or pigmented nail (reddish, purple, brown, black, or a combination), which may be painless, tender, or painful.

Question 30

What are the causes of sungunal haemorrhage ?

Answer 30

Typically caused by trauma to the nail: * A recalled painful event (eg, crush injury or blunt trauma) * A non-recalled repetitive micro-trauma (eg, tight or ill-fitting shoes).