Disease of the nails

Question 1

What can cause discolouration of the nails?

Answer 1

Excess licking

Question 2

What are the main presentations beyond trauma + pruritic change?

Answer 2

1. Nail breakage and shedding
2. Purulent discharge, erythema and/or swelling of the nailbed (paronychia)

Question 3

What are the differential diagnoses of diseases with nail breakage + shedding restricted to the nails?

Answer 3

• Symmetrical lupoid onychodystrophy
• Dermatophytosis (cutaneous lesions possible)
• Trauma
• Neoplasia

Question 4

What are the differential diagnoses of diseases with nail breakage + shedding that are widespread?

Answer 4

• Various IMSDs including vasculitis
• Leishmaniasis

Question 5

What are the clinical signs of symmetrical lupoid onychodystrophy?

Answer 5

• Multiple nails affected with acute or subacute onset
• Sloughing/loss of nails (onychomadesis)
• Breakage of brittle nails (onychorrhexis)
• Splitting of nails (onychoschizia)
• Nail pain (onychalgia)
• Haemorrhage within the nail (subtle and not visible in pigmented nails)
• Paronychia (2 ̊ to loose nails or occasionally SBI)

Question 6

How is symmetrical lupoid onychodystrophy diagnosed?

Answer 6

• Clinical diagnosis: typical history and clinical signs
• Cytology: rule out microbial infection
• Imaging: rule out neoplasia in digits with chronic paronychia

Question 7

How is symmetrical lupoid onychodystrophy treated?

Answer 7

• EFAs: high dose
• Prednisolone: 1-2 mg/kg SID then taper and switch to topical therapy e.g. hydrocortisone aceponate (Cortavance)
• Analgesia: very important, paracetamol
• Biotin supplementation and nail care via regular filing

Question 8

What is the clinical signs of dermatophytosis causing nail breakage?

Answer 8

• Nails soft, crumbly and fragmented (invaded by fungal hyphae)
• Nail pain (onychalgia)
• Usually 1 or 2 (localised nail disease) nails affected (cf SLO) but often see lesions elsewhere on body

Question 9

What are common neoplasias of the ungual fold?

Answer 9

Squamous cell carcinoma
Melanoma

Question 10

What are the differential diagnoses of paronychia?

Answer 10

1. Malassezia overgrowth
2. Bacterial infection
3. Immune-mediated diseases (especially pemphigus foliaceus)
4. Neoplasia

Question 11

What is paronychia?

Answer 11

infection of tissue fold around the nails

Question 12

What is the most common type of paronychia?

Answer 12

Malassezia paronychia - usually secondary to allergic skin disease