Did you know only about 50% of discolored or thickened, dystrophic-appearing, nails have a fungal infection?
It is possible for the layman to believe a thickened nail must mean a nail fungus is present. When concern a person has a nail fungus presents itself, before treating them cosmetically, it is best to refer the person to their general practitioner who can refer them to a podiatrist or dermatologist to correctly identify the condition if needed. Only about 50% of discolored or dyst
rophic-appearing nails have a fungal infection confirmed with culture. And 20% of the adult population has onychomycosis, nail fungus.
There are many other causes for a nail to become thickened or discolored. Treatment like chemotherapy can cause changes in the nail matrix and cause an overproduction of nail cells that form the nail plate. Older people are at an increased risk of nail alterations, including normal age-related changes and disorders that more commonly affect this specific population. Secondary factors are important contributors to pathologic nail changes, including impaired circulation at the distal extremities, faulty
biomechanics, infections, neoplasms, and skin or systemic diseases with nail manifestations.¹
The many other causes of nail thickening and discoloration, which are not a fungus, include:
1. Onychogryphosis thickening and distortion of the nail, typically of the big toe, thought to be due to previous nail bed trauma.²
2. Onychauxis, an overgrowth or thickening of the nail, reveals nothing to the casual observer, the tech, or the doctor. Many times, in fact, onychauxis is a natural part of aging.3
If the thickening is caused by a fungus it “can sometimes be cured,” says Dr. Schumacher. “When a nail is thick because of a fungal infection” ” treatment of the infection may cure the nail.” In cases like this, the nail may be able to grow in healthy after the primary condition has been resolved. However, if onychauxis is caused by trauma and the matrix is damaged, it’s more likely that the thickness will need to be maintained through regular manicures or pedicures, because the nail may continue to grow in thicker than normal nails. Since a doctor must determine a cause before treatment is recommended, there is not a standard treatment for onychauxis. 4
3. Trauma (tight shoes, nail-biting).
4. Poor foot care.
5. Eczema (irritant or allergic contact dermatitis).
6. Lichen planus.
7. Subungual melanoma.
8. Psoriatic nail disease. Psoriasis can affect the skin, nails, and joints. Classically, psoriatic nail disease consists of onycholysis; salmon (oil) spots (discolored areas that represent nail bed psoriasis); an irregular pitting pattern; and onychauxis. The Koebner phenomenon, or the appearance of lesions at the site of in
jury, can also occur in the nails and may manifest in an asymmetrical presentation. If a patient presents with an onychomycosis-like nail involvement and has failed oral antifungals, one should consider a diagnosis of psoriatic nail disease. Also, if psoriatic plaques and nail dystrophy are present, they do not automatically lead to a diagnosis of psoriatic nail disease. This is why culture and biopsy with negative PAS stain are essential to achieving the correct diagnosis.5
9. Bacterial paronychia – e.g., Pseudomonas spp. infection.
10. Systemic disease – e.g., thyroid disease, diabetes, peripheral arterial disease.
11. Rare systemic disorders – e.g., keratosis follicularis (Darier’s disea
se), yellow nail syndrome, nail-patella syndrome, pachyonychia congenital.
12. Idiosyncratic drug reaction (especially tetracyclines, quinolones and psoralens).
It is a “nail myth” that “nail thickness is caused by separation of the nail layers.”
The layman explanation to most of the causes of a thickened nail, items in the above list, is due to changes in the matrix which produce the nail cells. Nail cells move up the nail bed after being produced. When the matrix experiences change due to trauma, circulation or disease, it can create an overproduction of nail cells creating the thickened nail.
The technical term for layers of the nail separating is Onychoschizia. It is the transverse and lamellar splitting of the free edge and nail plate. The causes are excess wetting and drying of the nail, trauma, nail enhancements or polish, and systemic diseases. But does not include thickening of the nail.
Nail fungus caused by dermatophytes can cause an illusion of a thickened nail. The invasion of the organism causes mild inflammation, the skin under the nail to thicken (focal parakeratosis), and an overproduction of keratin (subungual hyperkeratosis) which push the nail up from the nail bed creating an illusion of thickness.6
Older people are at an increased risk of nail alterations, including normal age-related changes and disorders that more commonly affect this specific population. Secondary factors are important contributors to pathologic nail changes, including impaired circulation at the distal extremities, faulty biomechanics, infections, neoplasms, and skin or systemic diseases with nail manifestations.7
Holding a nail technology or cosmetology license makes you the best advocate for the people who trust and look to you for your expert advice your license gives you, and the knowledge to know when to refer them to a physician. You were trained and tested on nail disorders and diseases. When in doubt always refer to a physician. Holding a nail technology or cosmetology license does not prevent you from educating yourself beyond the nail technology course. Always follow your state board guidelines regarding this topic when it comes to treating your clients cosmetically.
Links to supporting documentation are included in this post.
Definitions that are not explained above.
Nail dystrophy refers to poor nail formation, usually as the result of trauma or infection. When caused by trauma, the nail becomes discolored due to blood pooling underneath the nail. Over time, the nail breaks away from the nail bed until it detaches completely.8
For more continuing education on the nail industry visit The Meticulous Manicurist Nail Tutorials