A. Onychomycosis (Paronychia)

1. Dermatophyte infections of nails
2. Toenails more commonly affected than fingernails
   1. Ridged discolored nails are common findings
   2. Multiple nails are usually affected, often bilaterally
3. Rarely responds adequately to topical therapy
   1. Terbinafine (Lamisil®) is topical agent of choice
   2. Mycocide NS is a topical anti-fungal with good activity in paronychial disease
   3. Ciclopirox 8% (Penlac® lacquer) - effective for paronychia without lunula involvement
4. Systemic Therapy
   1. Typically more effective than topical
   2. Oral griseofulvin (Fulvicin®) formerly drug of choice; therapy for 6-12 months
   3. High rate of hepatitis with griseofulvin, and common relapses on stopping drug
   4. Terbinafine is agent of choice
5. Terbinafine (Lamisil®)
   1. Oral terbinafine 250mg po qd for 6-12 weeks very effective
   2. Better tolerated and less expensive than itraconazole
6. Itraconazole (Sporanox®)
   1. 200mg po qd for 4-12 weeks is often effective and well tolerated
   2. May also be given 1-2 weeks per month for 3-6 months and be effective

B. Koilonychia (Spoon Nails)

1. Thin, concave nail plates with everted edges
2. Usually seen in association with faulty iron metabolism
   1. Iron deficiency anemia
   2. Plummer-Vinson Syndrome
   3. Hemochromatosis
3. Other Associations
   1. Coronary Disease
   2. Syphilis
   3. Hyperthyroidism
   4. Idiopathic (no obvious cause or association)

C. Clubbing [2]

1. Characteristics
   1. Flattened Nail beds
   2. Loss of space between nails when dorsal fingers of either hand are placed together
   3. Use of profile angle and phalangeal depth ratio for quantitation of clubbing
2. Associated with hypertrophic osteoarthropathy (HTOA)
   1. HTOA is a systemic disroder of bone and joints
   2. Abnormal proliferation of skin and osseous structures at distal extremities
   3. Periostosis of the tubular bones with synovial effusions also occurs
3. Diseases Associated with Clubbing
   1. Chronic Cardiac Disease - particularly congenital
   2. Chronic Pulmonary Disease - particularly congenital
   3. Bronchogenic carcinoma
4. Hepatic Disease - Cirrhosis and Carcinoma
5. Intestinal Disease - Inflammatory bowel disease, polyps, carcinoma, chronic infections
6. Mediastinal Tumors - Esophageal Carcinoma, Thymoma
7. Other Diseases - Graves' Disease, Infective arteritis, Hemiplegia, others

D. Lichen Planus [3]

1. Cell mediated cytotoxic effects on stratified squamous epithelium
2. Typically affects skin with oral OR nail lesions
3. Nail lesions include damaged or lost nails ("20-nail dystrophy")
4. Good response to oral glucocorticoids

E. Spinter Hemorrhages

1. Due to ruptured capillaries, often with clot formation
2. May be due to trauma, infection, or other thromboembolism
3. Typically purple spots under nail bed, may also occur on tips of digits
4. Endocarditis is typically associated with these hemorrhages

F. Periungal Telangiectasias

1. Dilated capillary loops in distal digits, juxtaposed to nails
2. Strongly associated with secondary Raynaud's Disease
3. Most Common Systemic Diseases
   1. Dermatomyositis
   2. Systemic Sclerosis (CREST and Scleroderma)
   3. Systemic Lupus Erythematosus

G. Nail Pitting

1. Nearly always associated with psoriasis
2. More common in patients with psoriatic arthritis and psoriasis
3. Psoriasis affects finger nails 50% of patients, toe nails ~35% of patients

H. Yellow Nail Syndrome

1. Triad of Yellow Nails, Lymphedema, Exudative Pleural Effusions
2. Due to lymphatic obstruction (blocked lung drainage)
3. Often with bronchiectasis, recurrent pneumonia, infections

I. Keratosis Follicularis (Darier's Disease)

1. Red and white longitudinal nail bands, distal nicking of nail plate
2. Autosomal dominant disorder
   1. Greasy, brown, keratotic papules on upper body and face
   2. Macerated papules and plaques, usually intertriginous
   3. Abnormal oral mucosa with cobblestone appearance
   4. Spinter hemorrhages in nails

References

1. Tosti A and Piraccini BM. 2000. Dermatol Clin. 18(2):339
2. Myers KA and Farquhar DRE. 2001. JAMA. 286(3):341
3. Gallagher GT and Lyle S. 2002. NEJM. 347(6):430 (Case Record)