From the Guidelines
Nail bed discoloration should be evaluated for underlying causes, with fungal infections, trauma, and bacterial infections being common culprits, and treatment should be guided by the specific cause, as indicated by the British Association of Dermatologists' guidelines for the management of onychomycosis 1. When assessing nail bed discoloration, it's essential to consider the clinical presentation, including the color, location, and presence of other symptoms.
- Green or black discoloration may suggest a bacterial infection, particularly Pseudomonas aeruginosa, as noted in the British Association of Dermatologists' guidelines 1.
- Yellowing of the nail can indicate a fungal infection, while blue or black discoloration might result from trauma or melanoma.
- White spots often reflect minor trauma, and horizontal lines (Beau's lines) may indicate systemic illness. The diagnosis of nail bed discoloration can be challenging, as various conditions can mimic onychomycosis, including chronic trauma, psoriasis, onycholysis, and subungual malignant melanoma, as discussed in the guidelines 1. A thorough examination, including a clipping of the infected nail area and examination of the nail bed, can help differentiate between nail trauma and onychomycosis, with the nail bed appearing normal in cases of trauma 1. Treatment should be tailored to the underlying cause, with antifungal medications, such as terbinafine, being effective for fungal infections, and corticosteroid creams potentially beneficial for psoriasis-related discoloration. Given the potential for nail discoloration to signal underlying health conditions, persistent or worsening discoloration should prompt medical consultation, especially when accompanied by pain, nail separation, or spreading to multiple nails.
From the Research
Nail Bed Discoloration
- Nail bed discoloration can be a symptom of various nail conditions, including onychomycosis, a fungal nail infection that causes nail discoloration, thickening, and separation from the nail bed 2.
- Onychomycosis is a common nail disorder that can be caused by a variety of organisms, but most cases are caused by dermatophytes 2.
- The diagnostic work-up of nail disease, including nail bed discoloration, should include a detailed history and clinical examination of all 20 nail units, as well as dermoscopy, diagnostic imaging, and histopathologic and mycological analyses 3.
- Treatment of onychomycosis, which can cause nail bed discoloration, includes topical and/or systemic medications, such as efinaconazole and terbinafine, as well as discontinuation of offending drugs or surgical intervention 4, 5.
- Patient education on proper nail care and techniques to minimize further damage to the affected nails is also important in managing nail bed discoloration 3.
Causes of Nail Bed Discoloration
- Fungal infections, such as onychomycosis, can cause nail bed discoloration 4, 2.
- Other nail conditions, such as brittle nail syndrome, paronychia, nail psoriasis, longitudinal melanonychia, Beau's lines, onychomadesis, and retronychia, can also cause nail bed discoloration 3.
- Systemic diseases or infections can also cause nail changes, including nail bed discoloration 3.
Treatment Options
- Topical treatments, such as efinaconazole, can be effective in treating onychomycosis and nail bed discoloration 4.
- Systemic antifungals, such as terbinafine, can also be effective in treating onychomycosis and nail bed discoloration 5, 2.
- Surgical intervention, such as nail avulsion, may be necessary in some cases of nail bed discoloration 6.