Regional dermatology Nail diseases Chapter 13 Regional dermatology Nail diseases

The nail Provide strength and protection for the terminal phalanx. Helps with fine touch and handling of small objects. Matrix Produce keratin Runs from the proximal end of the floor of the nail fold to the distal margin of the lunule. From this area the nail plate grows forward over the nail bed, ending in a free margin at the tip of the digit. Nail bed Producing small amounts of keratin which contribute to the nail and responsible for the ‘false nail’ formed when the nail matrix is obliterated by surgery or injury. Cuticle Protect the potential space of the nail fold from chemicals and from infection.

Effects of trauma Chronic trauma: Lamellar splitting (housewives) Permanent ridges or splits in the nail plate Splinter haemorrhages also be a feature of Psoriasis of the nail Subacute bacterial endocarditis Larger subungual haematomas (exlude subungual melanoma) Chronic trauma: Onychogryphosis Haemorrhage under the nails of the big toes Gross thickening of toenailsnail Ingrowing nail Onycholysis Bitten nail Lamellar splitting (housewives)

Fig. 13. 21 A subungual haematoma of the big toe Fig. 13.21 A subungual haematoma of the big toe. Although there was no history of trauma we were happy to watch this grow out over 6 months as the appearance was sudden, the colour was right and the nail folds showed no pigment. Fig. 13.20 Gross splinter haemorrhages caused by trauma. Fig. 13.22 Onychogryphosis

Onycholysis A separation of the nail plate from the nail bed May be a result of Minor trauma Nail psoriasis Phototoxic reactions Repeated immersion in water Use of nail hardeners Hyperthyroidism (esp, 4th toe) Usually, no cause for it is found. The space created may be colonized by yeasts, bacteria such as P.aeruginosa.

Onycholysis Minor trauma Onycholysis The yellow color may indicate a secondary Candida infection. Psoriasis and tinea have a similar ppearance Onycholysis Involvement of many nails

Spoon nails Onycholysis—trauma Habit-tic deformity Onycholysis—secondary infection Leukonychia Distal splitting

Ridging Beau's lines, Median nail dystrophy Chronic paronychia Acute paronychia

Subungual hematoma Splinter hemorrhages Trauma Pseudomonas colonized Plate hypertrophy

The nail in systemic disease Clubbing Koilonychia (IDA) Half-and-half nail (Colour changes) Beau’s lines Connective tissue disorders (Nail fold telangiectasia)

Clubbing A bulbous enlargement of the terminal phalanx With an increase in the angle between the nail plate and the proximal fold to over 180° Association with Chronic lung disease Cyanotic heart disease Familial (rare) Severe clubbing was accompanied by hypertrophic pulmonary osteoarthropathy.

Colour changes half-and-half nail Chronic renal failure White proximal Red or brown distal half Liver cirrhosis  hypoalbuminaemia Whitening of the nail plates Drugs can discolour the nails, as: Antimalarials Antibiotics Phenothiazines

CT disorders Nail fold telangiectasia or erythema Physical sign in Dermatomyositis (cuticles become shaggy) Systemic sclerosis (finger pulp leads to overcurvature of the nail plates) SLE Peripheral circulation is impaired (Raynaud’s phenomenon) Thin nails Longitudinal ridging Partial onycholysis Fig. 13.27 Large tortuous capillary loops of the proximal nail fold signal the presence of a connective tissue disorder.

Nail changes in the common dermatoses Psoriasis Arthritis  more likely severe nail involvement is. Nail changes Pitting of the surface of the nail plate (best-known) Oil spots: red/brown areas under the nail plate Onycholysis No effective topical treatment

Psoriasis—pitting Psoriasis—onycholysis Psoriasis-plate alteration Oil spot

Eczema Itchy chronic eczema  polish nail by scratching. Eczema of the nail folds may lead to coarse irregularity with transverse ridging of the adjacent nail plates. Lichen planus 10% have nail changes. Mostly reversible Thinning of the nail plate Irregular longitudinal grooves and ridges. Pterygium (more severe), which the cuticle grows forward over the base of the nail & attached to the nail plate. The threat of severe and permanent nail changes can sometimes justify treatment with systemic steroids. Alopecia areata More severe the hair loss  more likely nail involvement. Roughness or fine pitting on the surface of the nail plates Lunulae may appear mottled.

Alopecia areata. Shallow pitting occurs in some patients with alopecia areata. Lichen planus. Inflammation of the matrix results in adhesion of the proximal nailfold to the scarred matrix, a pterygium

Acute paronychia Inflammation of the nail fold by Staphylococcus infection Enter through break in the skin or cuticle Rapid onset of painful, bright red swelling Pus in the nail fold or under the nail Treatmnet: systemic treatment (flucloxacillin, cephalexin or erythromycin) Inscision & drainage

Acute pain and swelling of the lateral nailfold Erythema and purulent material occur at the proximal nailfold Elevation of the lateral nailfold releases a large amount of purulent material. Pain is relieved immediately

Chronic paronychia Presentation: Tender Swollen nail folds Opportunistic pathogens (yeasts, G+ve cocci & G-ve rods) colonize the space between the nail fold and nail plate, producing a chronic dermatitis. Predisposing factors: Poor peripheral circulation Wet work Working with flour Diabetes Vaginal candidosis Overvigorous cutting back of the cuticles Presentation: Tender Swollen nail folds pus discharge Loss cuticular seal Ridged and discoloured adjacent nail plate The condition may last for years.

Dermatophyte infection Investigations: Test the urine for sugar DDx: Amelanotic melanoma. Dermatophyte infection Investigations: Test the urine for sugar Check for vaginal and oral candidosis Culture (pus Treatment: Stop manicuring of the cuticle Keep hands warm & dry Imidazole cream Highly potent topical corticosteroid creams Itraconazole Paronychia with secondary nail ridging Erythema and swelling of the nailfolds. The cuticle is absent. Horizontal ridging of the nails

4 types of onychomycosis showing different entry points by infecting organisms.

White superficial onychomycosis Proximal subungual onychomycosis Distal subungual onychomycosis Candida onychomycosis All of the fingernails are infected

Dermatophyte infections Tinea unguium. T. rubrum & T. mentagrophytes are responsible for most nail infections also Candida can infect the nail plate Associated with tinea pedis The early changes often occur at the free edge & spread proximally Nail & HIV infections often involve the proximal subungual skin without distal. Presentation: Yellow, crumbly & thickened nail plate . DDx: Psoriasis Yeast and mould infections Investigations: KOH Culture Treatment: Seldom clears spontaneously Systemic anti-fungal