| Table 3-31 Nail Disorders |
| | Entity | | Clinical Findings | | Associated Diseases |
| Nail matrix |
| | Beau’s lines
(Figure 3.58D) | | Transverse depression in nail plate
surface | | Severe systemic event (all nails) or
trauma/disease of matrix (single nail) |
| | Hapalonychia | | Soft nail plate | | |
| | Koilonychia
(Spoon nails) | | Thin, concave nails with eversion of free nail edge | | Hereditary, physiologic (children), iron deficiency, thyroid abnormality |
| | Leukonychia, diffuse | | Opaque or completely white nail plate | | Chemotherapy, white superficial
onychomycosis, congenital disease |
| | Leukonychia, punctate | | White macules on nail plate | | Psoriasis (PSO), trauma to matrix |
| | Leukonychia, transverse
(striate) (Figure 3.57E) | | Narrow white transverse lines along nail plate | | Trauma to matrix |
| | Mee’s lines | | Transverse lines of entire nail breadth in all nails | | Arsenic poisoning, trauma, medications, severe illness, PSO (flare) |
| | Onychomadesis
(Nail shedding) | | Detachment of nail plate from proximal nail fold (PNF) → shedding of nail | | Traumatic, medications (i.e. chemo), drug reaction (i.e. TEN), autoimmune diseases, systemic illness |
| | Onychorrhexis
(Figure 3.58E) | | Longitudinal ridging, ± fissuring of plate | | Lichen planus, chronic trauma, repeated wet/dry cycles, normal with aging |
| | Pitting
(Figure 3.57A) | | Punctate depressions of nail plate surface
{Elkonyxis: large 2-mm pits} | | Psoriasis (PSO), alopecia areata,
eczema |
| | Red lunula | | Pink to red spots within lunula | | Alopecia areata, rheumatoid arthritis, LE, CHF, CO poisoning |
| | Trachyonychia (20 nail
dystrophy) (Figure 3.57C) | | Rough, thinned nails with longitudinal ridging | | Alopecia areata, lichen planus (LP), PSO, eczema |
| Nail bed |
| | Apparent leukonychia | | White discoloration (fades with pressure); nail plate looks white but normal color | | Drugs (i.e. chemo agents) or systemic disease |
| | Oil spots
(Figure 3.57B) | | Brown spots under nail plate | | PSO |
| | Onycholysis
(Figure 3.57F) | | White discoloration at distal end where nail plate separated from bed | | PSO, trauma, onychomycosis, medications (TCN, NSAID, PUVA), tumors, systemic diseases (hyperthyroidism), pregnancy |
| | Splinter hemorrhages
(Figure 3.59A, B) | | Rough, thinned nails with longitudinal ridging | | Alopecia areata, lichen planus (LP), PSO, eczema |
| Nail color |
| | Half and half nails
(Lindsay’s nails)
(Figure 3.59C) | | Proximal ½ with white zone, distal ½ with red-brown zone | | Chronic renal disease |
| | Hutchinson’s sign | | Periungual black discoloration | | Melanoma |
| | Muehrcke’s bands | | Transverse white bands parallel to lunula | | Hypoalbuminemia, chemotherapy |
| | Melanonychia | | Partial or diffuse | | Drugs, melanoma, Laugier-Hunziker |
| | Longitudinal melanonychia
(Melanonychia striata)
(Figure 3.58F) | | Vertical brown-black band (proximal to distal margin)
{Common in darkly pigmented skin types} | | Nevus, lentigo, drugs, trauma, melanoma |
| | Terry’s nails
(Figure 3.59D) | | Proximal 2/3 white nail color, distal
1/3 brown-pink band | | Cirrhosis, hypoalbuminemia, diabetes, cardiac disease |
| Others |
| | Absent lunula | | No visible lunula | | Yellow nail syndrome, renal failure, trauma |
| | Anonychia | | Absence of nail | | Nail patella syndrome, COIF, (Congenital Onychodysplasia of the Index Finger) scarring |
| | Blue lunula | | Blue discoloration of lunula | | Wilson’s, drugs, PUVA, argyria, etc. |
| | Brachyonychia | | Short, wide nails | | Rubinstein-Taybi syndrome, PSO |
| | Clubbing | | ↑ Nail curvature w/ bulbous growth of tip of digit | | Chronic pulmonary disease, idiopathic, familial, systemic disease |
| | Dolichonychia | | Long nails | | Marfan’s, Ehlers Danlos, etc. |
| | Dorsal pterygium
(Figure 3.58C) | | Wing-like growth fusing PNF with nail bed/matrix | | Lichen planus, epidermal bullosa, TEN, GVHD, TEN, cicatricial pemphigoid |
| | Habit tic deformity
(Figure 3.58A) | | Parallel horizontal grooves | | Caused by repetitive trauma to cuticle |
| | Macronychia | | Large nails | | Congenital abnormality |
| | Median canaliform dystrophy
(Figure 3.58B) | | Inverted ‘fir tree’(oblique lines from midline defect) | | Idiopathic or inherited |
| | Micronycha | | Small nails | | Congenital defect (i.e. COIF) |
| | Onychauxis | | Hypertrophic nail plate | | May be due to chronic trauma |
| | Onychoatrophy | | Reduction in size and thickness of nail plate | | LP, vascular insufficiency, systemic disorders, medications |
| | Onychocryptosis | | Ingrown nail | | |
| | Onychogryphosis | | Grossly thickened and long nail, resembling claw | | Inability to cut toenails, long-term pressure (i.e. shoes), neglect |
| | Onychophagia | | Nail biting | | |
| | Onychoschizia
(Lamellar nail splitting) | | Distal lamellar separation into horizontal layers | | Repeated wet and dry cycles, trauma, systemic disease and medications |
| | Onychotillomania | | Chronic picking of nail | | |
| | Pachyonychia | | Thickened nails | | Pachyonychia congenita |
| | Pincer nails | | Overcurvature lateral portion | | Pressure (ill-fitting shoes), hereditary |
| | Platyonychia | | Flat nail | | Inherited or acquired |
| | Racket nails | | Distal phalanx short/wide | | Form of brachyonychia |
| | Subungual exostosis
(Figure 3.59E, F) | | Painful, bony subungual growth elevating nail plate | | X-ray confirms bony exostosis |
| | Triangular lunula | | Triangular shape of lunula | | Nail-patella syndrome |
| | Ventral pterygium
(Pterygium inversum unguis) | | Fusion of hyponychium to distal nail plate | | Familial, trauma, systemic sclerosis, lupus erythematosus |
| | Yellow nails | | Yellow color to nail plate | | Yellow nail syndrome, drugs, chronic enamel
{Yellow nail syndrome: pulmonary disorder + lymphedema + yellow, slow growing nails with absent lunulae} |
| | V-shaped nicking
(Figure 3.57D) | | V-shaped nick at free margin | | Darier disease |
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