Unless otherwise stated, all treatments and doses are for adults and not weight based for the pediatric population.
Case Example:
A 48-year-old female patient presents to your clinic for abnormal findings in her toes. She knows that the summer season is coming up and the abnormal appearance of her toenails is very concerning to her. She is a regular patient to your clinic, routinely seen for type 2 diabetes mellitus that is poorly controlled.
Let’s review some anatomy (Scher RK)
If you were to look at the cross section of your digit, you would see that the nail bed is covered by the nail plate. The most proximal portion of the nail bed is the blood supply and the growth region, called the nail matrix, which provides the epithelial cells for nail plate growth. When it comes to the conditions discussed in this review, damage to the matrix is key in causing many of the irregularities experienced: longitudinal lines, roughness, pitting, brittleness, and transverse lines. Overlying the nail on the proximal end is the cuticle (skin). On either side (lateral) of the nail are the nail folds. Just below the nail bed is the distal phalanx and periosteum. Due to the close proximity, any condition that affects the bone can affect the nail, and vice versa.
Important Conditions Associated with Abnormal Nail Exam
Can manifest with nail pitting, leukonychia, and an oil drop sign on the nail bed. Look for cutaneous psoriasis as a coexisting feature.
Can present acutely or in a chronic manner with tender, erythematous swelling and folding on the lateral portions of the nail. Treat with warm saline soaks and, if a concurrent abscess is present, possible drainage with antibiotics targeted to Staphylococcus aureus (if acute) and gram negatives with Candida (if chronic). (Rigopoulos D, 2008)
Splinter hemorrhages
Classically associated with subacute bacterial endocarditis; they can be seen with vitamin C deficiency as well.
Classically associated with severe pulmonary disease (COPD, lung cancer) causing hypertension and a chronic state of hypoxia; can also be associated with inflammatory bowel disease. Look for painless bilateral enlargement of the nail fold angles of all fingers and toes and a positive Schamroth sign. Consider testing HIV, TSH, LFTs, and CBC. Treatment is centered on the underlying cause. (Chumley HS)
Presents as transverse grooves or furrows in the nail. Generalized causes include medication side effects (ie, retinoids for acne), liver/cardiac/renal failure, carpal tunnel if present on only one extremity, postsurgical complication from tourniquet use, and regional pain syndrome. If only one or a few digits are involved, hand-foot-and-mouth disease should be considered. (LeBlond RF)
Mees’ Lines
Also known as transverse white nail lines, can be seen during periods of stress, renal failure (acute), heart failure, inflammatory bowel disease, SLE, and malignancy. In the right clinical setting, consider toxic metal exposure (ie, thallium). (Lipner SR, 2016)
Hutchinson Sign
Melanoma in situ manifesting as a pigmented linear line (brown to black) from the matrix to the perionychium and typically a poor prognostic indicator as it could represent radial-growth phase melanoma. Such bands, which typically have a sudden onset and growth, often affect only a single digit (commonly the thumb). Such patients, who are typically in their 60-80s with a family history of melanoma, should be referred to a dermatologist for dermoscopy to be performed with biopsy. (Lipner SR, 2016)
Nail Conditions by Matrix Involvement (Richert, 2015)
Proximal Matrix
Longitudinal Ridging
- Presents as shallow ridges, which can be physiologic (if multiple are noted) or associated with trauma (when a single ridge is present) and become more apparent as we age. When pathologic, associated with rheumatoid arthritis and peripheral vascular disease. (Michel C, 1997)
Longitudinal Grooves
- Longitudinal Grooves – Also called Beau lines or transverse lines, present as depressions in part or the entirety of the nail affecting one or all of the nails. When multiple fissures are noted, termed onychorrhexis. Mucoid cysts may be present if a single smooth gutter is noted.
Pitting
- Small depressions on the surface of the nail that vary in size and shape with no clear pattern of distribution. Most commonly present on the toenails, look for other dermatologic manifestations that may suggest underlying psoriasis (typically only seen with > 20 pits on nails), atopic dermatitis, alopecia, or lichen planus.
Distal Matrix
Leukonychia
- Nail will appear white due to abnormal keratinization of the nail matrix. May present in a half-and-half appearance that goes away with distal pressure. Myriad causes, some associated with trauma (preceded by subungual hematoma); if the lines are transverse (termed Mees’ lines), look for atypical causes such as arsenic poisoning, parasitic infections, and reactions to chemotherapy.
Erythronychia
- Red discoloration of the nail matrix that disappears with pressure and is associated with systemic conditions such as psoriasis, lichen planus, and alopecia areata.
Melanonychia
- Melanin deposited in the nail plate showing up as bands. The color can vary.
What nail findings are seen with increasing age?
While many nail findings can be physiologic, due to deficiencies in either vitamins or minerals, or associated with systemic disorders, there are others that occur with increasing frequency simply due to progressing age. Examples include brittle nails, onychocryptosis, onychomycosis, and subungual hematomas.
As its name implies, patients will experience splitting of the nails on the free edge at the distal region of the nail. Oral biotin supplementation can be helpful. Have the patient avoid topical cosmetics and repetitive trauma, if possible.
May look similar to paronychia; look for inflammation of the lateral nail fold. Conservative treatment with partial removal of the affected nail portion is helpful. Preventive measures include teaching appropriate nail cutting technique and evaluating shoes to ensure they are not too small of a fit. (Martínez-Nova A, 2007)
Onychauxis
Hypertrophy of the nail leading to shrinkage and discoloration. Can be painful and may be hard to distinguish from concurrent onychomycosis. Can be due to repetitive trauma from poor shoe compatibility and chronic toe contracture.
The most common nail infection of fungal origin, most often affecting the toenails, presenting with yellow patchy discoloration with nail thickening. Increased risk seen with older age and smoking; there has been genetic predisposition found. Treatment is targeted toward Trichophyton species, but other species such as Candida and Scopulariopsis have been reported. Treatment can be difficult and may require nail removal with systemic therapy (oral terbinafine). (Gupta AK, 2006) In the right population, consider testing for HIV. (Surjushe A, 2007)
Associated with trauma; look for a painful red discoloration under the nail that moves forward with time. Can be mistaken for melanoma; therefore, if there is no trauma history, consider referral for biopsy. If acute pain is noted, it responds well to pressure relief by drilling a hole (can use an 18-g needle) into the nail plate. Avoid damaging the nail matrix.
Conclusion
The above patient’s diagnosis was onychomycosis, likely secondary to her poorly controlled diabetes. She was placed on an oral prescription of terbinafine, and she was followed up with 2 months later with resolution of her symptoms. If the symptoms had not improved, then a podiatry consultation could be considered for toenail removal.
The nail is a gateway into the body and can help reveal underlying systemic conditions. It is important not to forget about nail evaluation when performing your general physical exam.
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