Although dermatologic manifestations are now recognized as part of COVID-19, specifics of nail manifestations in particular are not widely known. In an article published in Dermatologic Therapy, dermatologists review the most updated knowledge on nail involvement for those with COVID-19 and the recommended treatment options.
- An open trial of 82 COVID-19 patients in Italy reported pericapillary edema (80.5%), enlarged capillaries (61%), and sludge flow (53.7%), as well as meandering capillaries and reduced capillary density in every second patient.
- Hemosiderin deposits from micro-hemorrhages and micro-thrombosis has been reported.
- Patients recovered from COVID-19 reported a higher frequency of capillary pathologies including enlarged capillaries, meandering capillaries, capillary loss, and empty dermal papillae.
- Microvascular disturbances may be detected via nailfold capillaroscopy.
COVID-toe or -finger
- A pernio-like periungual erythematous edema on the fingers or toes.
- Typically occurs as part of a resolution phase or a milder/asymptomatic course of COVID-19.
- Histopathological findings of 17 patients with pernio-like acral lesions and suspected SARS-CoV-2 infection revealed deep horizontal parakeratosis (71%), necrosis of epidermal keratinocytes (41.5%), dispersed or confluent basal cell vacuolation (18%), spongiosis (12%), lymphocytic exocytosis (12%), dermal edema (76.5%), perivascular dermal lymphocytic infiltrate (100%), perivascular eosinophils (23.5%), endothelial cell swelling (65%), dermal mucin deposits (41.5%), microthrombi in superficial capillaries (12%) or venules (6%), dermal fibrin deposits (12%), and fibrin deposits in venule walls (18%).
- Other studies reported cryofibrinogenemia; bilaterally localized distal erythematous or cyanotic lesions; red dots, white rosettes, and white streaks on dermatoscopy; histological remodeling of dermal blood vessels with a lobular arrangement, vascular wall thickening and a mild perivascular lymphocytic infiltrate; erythematous and purpuric papules on the toes or fingers, along with edema and pruritis or a burning sensation; and superficial dermal lymphocytic infiltrates around vessels and eccrine sweat glands.
- About 50% of patients in these studies were positive for SARS-CoV-2, and most were young.
- A rare but severe symptom.
- A red flag for acute severe infection with multisystemic inflammation and cardiovascular malfunction.
Treatment for Microvascular Nail Symptoms
- Young, asymptomatic patients, or patients without confirmed SARS-CoV-2 infection – COVID-toe or -finger symptoms are self-limiting and will spontaneously resolve in 2 to 3 weeks.
- Basic microvascular treatment in early COVID-19 stages – combination of antiviral therapies (favipiravir, remdesivir, hydroxychloroquine, lopanivir plus ritonavir) with antithrombotic treatment.
- Basic microvascular treatment in later COVID-19 stages – antithrombotic therapy combined with treatments for cytokine storm (tocilizumab, dexamethasone, IL-1 or TNF-beta antagonists).
- Cryofibrinogenemia – oral corticosteroids with low-dose acetylsalicylic acid.
- Reported in children with MIS-C and adults recovering from severe COVID-19.
- Moisturizers to limit the symptoms
- Transverse grooves of the nails
- Single or multiple nails may be affected; mostly seen in fingernails
- Can be accompanied by leukonychia
- Observed in children and adults with COVID-19
- Mild and self-limiting; no specific treatment
- Separation of the nail plate from the nail matrix with persistent attachment to the nail bed.
- May be preceded by Beau’s lines.
- A late manifestation of COVID-19 is heterogenous red-white discoloration of the nail bed with distal onycholysis.
- Mild and self-limiting
- High-energy 633 nm red light (126 J/cm2 for 20 min every day) has been successful for fingernails but not toenails
Discolorations of the Lunula and Nail Plate
- Red violet band surrounding the distal margin of the nail lunula and orange discoloration of the nail plate.
- Lunula discoloration has been reported in adults with acute SARS-CoV-2.
- Nail plate discoloration has been reported as a delayed response several weeks after COVID-19 diagnosis in elderly patients.
- Non-blanchable transverse leukonychia has also been reported, and may persist following severe damage to the nail matrix.
- No specific treatment; colored nail lacquers can hide discoloration
Nail Changes Induced by COVID-19 Treatments
- Yellow-white fluorescence on the nails
- Greenish-white fluorescence in the lunula and nail plate portion near the proximal nail fold
- Longitudinal melanonychia
- Nail changes will spontaneously resolve with withdrawal of the corresponding drug
Nail Changes Induced by COVID-19 Vaccination
- Pernio-like lesions on the hands and/or feet were reported several days after vaccination with Pfizer-BioNTech and Moderna vaccines.
- Low-dose acetylsalicylic acid with oral corticosteroids for symptomatic and painful lesions
- Treatment is often not necessary as symptoms are temporary
Nail Changes from COVID-19 Protective Measures
- Green nail syndrome (Goldman-Fox syndrome)
- Caused by nail infection or colonization with P. aeruginosa
- Known as an occupational disease in healthcare workers and was reported in healthcare workers during the COVID-19 pandemic
- Oral ciprofloxacin
- Topical treatments include removing the onycholytic part of the nail and brushing the nail bed with 2% hypochlorite solution twice daily for 6 weeks, as well as topical nadifloxacin, tobramycin, or gentamycin.
- Brittle nails and cuticle loss
- Due to chronic irritant proximal nail fold dermatitis
- Limit wet work and use of protective gloves
- Moisturizers during the day and emollients overnight
Wollina U, Kanitakis J, Baran R. Nails and COVID-19 – A comprehensive review of clinical findings and treatment. Published online Aug 16, 2021. Dermatol Ther. doi:10.1111/dth.15100