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Common‐sense advice for the treatment of selected nail disorders

2001; Wiley; Volume: 15; Issue: 2 Linguagem: Inglês

10.1046/j.1468-3083.2001.00179.x

1468-3083

Robert Baran,

Nonmelanoma Skin Cancer Studies

A number of nail disorders have been selected and common-sense advice for their treatment has been proposed. However, initially, the following should be borne in mind: Fingernails grow at a rate of 0.1 mm a day; toenails grow much more slowly (it takes 12–18 months to replace a large toenail). Except for transungual drug delivery systems, the nail plate prevents drug penetration into the nail bed and the matrix, which is itself covered by the proximal nail fold. It is, therefore, obvious that nail diseases may be chronic and/or difficult to treat. The disorders are arranged in alphabetical order to facilitate the reader searches. Burn injuries affecting the skin overlying the proximal nail fold may lead to exposure of the nail matrix. The associated pain, risk of infection, ragged appearance and potential injury to the nail matrix may be treated by a relocation of the retracted tissue and/or placement of a skin graft over the damaged area. Allergic or irritant contact dermatitis involving the digits may interfere with nail plate formation, produce and transverse grooves and pitting. Onycholysis is frequent. Paraben-free topical corticosteroids, applied three times daily to surrounding soft tissues, are effective, observing thorough protection of hands (cotton gloves beneath vinyl gloves). The best treatment is Mohs micrographic surgery allowing adequate excision with maximal preservation of normal tissue and function. This can be performed with routine instrumentation as well as with the carbon dioxide laser in a focused beam incisional mode, which avoids bleeding and ensures minimal postoperative discomfort for the patient. Excisional surgery may be used in some cases or for complete removal of the nail apparatus, with healing by secondary intention, grafting, or repair with a bridge flap. Electrosurgery is a therapeutic alternative in a very few selected cases. Liquid nitrogen may give good results in experienced hands. Both electrosurgery and liquid nitrogen do not allow adequate histological control of the tumour margins. Bone involvement requires amputation of the distal phalanx. Green nails are often thought to be due to infection with Pseudomonas, but in fact Pseudomonas just grows in a wet pocket under the posterior nail fold or under the nail. Drying out the pocket and using alcohol or an alcohol-based antibiotic such as clindamycin kills the organism, but discoloration persists until the nail grows out. Milton solution (sodium hypochlorite) one drop twice daily around the nail removes the stain. It is also possible to cover the nail with dark polish. Onychophagia (nail biting) and onychotillomania (neurotic picking or tearing of the nails) are nervous habits. Periungual warts are common in nail biters. Use distasteful preparations to discourage nail biting and chewing. Oral fluoxetine hydrochloride, 20 mg/d, may be useful. The longitudinal split known as Heller's median nail dystrophy is probably caused by repeated pressure on the base of the nail, the proximal nail fold of which is intact. It usually affects the thumbs and must be differentiated from the washboard nail, which results from pushing back the cuticle. Micropore tape, changed daily and kept on for 6 months, may deter the patient's habit. Chronic haematomas from ill-fitting footwear or sporting activities are painless and often associated with onycholysis of the large toenail. They sometimes grow out longitudinally and may occasionally persist, which makes partial nail avulsion necessary. Acute subungual haematomas are obvious clinically, occurring shortly after a single trauma involving the nail apparatus. The blood that accumulates beneath the nail plate produces pain, which may be severe. The size of the haematoma will determine the technique used for drainage. In partial haematoma of the proximal area of the nail apparatus, drainage of the haematoma with a fine-pointed scalpel blade gives prompt relief from pain. Hot paper clip cautery is an alternative to trephination the nail. Small haemorrhages progress distally, staining the deeper layers of the nail plate when subungual, or the upper layers when produced by trauma to the most proximal part of the matrix. Occasionally they may not migrate and must then be differentiated from naevi or melanomas. A haematoma involving more than 25% of the nail is observed often when there is injury to the nail bed. The possibility of an underlying fracture must be considered and an X-ray performed. After the nail plate is removed, the haematoma is evacuated and the wound repaired using 5-0 dexon. The nail is cleaned, shortened, narrowed and replaced by suturing to the lateral nail folds. The stitches are removed after 10 days. Systemic treatment: Etretinate 0.5 mg/kg per day or acitretin; nimesulid 200 mg/d. Topical treatment: Calcipotriol; topical steroids are helpful. Hangnails that may become infected should be removed with sharp-pointed scissors. Mupirocin ointment prevents or clears low-grade infection. Regardless of the initial cause, an ingrowing nail ultimately has a nail bed that is too narrow for its nail plate. Treatment depends on the degree, duration and type of the deformity. Avulsion of the nail or even spontaneous nail shedding may produce this condition. Sculptured artificial nails can be used to override the distal nail wall. When this procedure fails, a crescent wedge tissue excision is carried out around the entire distal phalanx, and the defect is closed with a 5-0 monofilament suture. Treatment of the early stage (pain and erythema) of this disorder is conservative. The nail spicule is removed under local anaesthesia, and a wisp of cotton wool, kept moist with a disinfectant, is placed beneath the nail and between the lateral border and the lateral groove. The nails should always be cut square along the top, and sharp corners should be smoothed away with an emery board. In advanced-stage (oedema, granulation tissue, purulent drainage), a lateral strip of the offending nail is removed. Haemostasis is achieved with a tourniquet and the blood is carefully cleared from the nail pocket. The surrounding skin is protected with petroleum jelly, and a saturated solution of phenol is applied to the lateral matrix horn on a small cotton pack for 3 min. Two major drawbacks to this procedure are (i) the long time required for healing, and (ii) the prolonged drainage caused by the chemical burn from the phenol's caustic effects, with possible secondary infections (treated by soaking the foot twice daily in a quart of warm water containing three capsules of Povidone-iodine (Betadine®). A thick, hypertrophic lateral nail fold results from long-standing ingrown nails. An elliptic wedge of tissue, taken from the lateral nail wall of the toe to the bone, pulls away the lateral nail fold from the offending lateral nail margin. Associated phenol cautery of the lateral matrix horn is advised. The nail brace technique, using a stainless steel wire fitted to the nail, is useful for correcting the inward distortion of the nail in this condition. Haneke's technique is suitable for a definitive cure. The nail is narrowed with bilateral cautery of the matrix horn, using phenol. The distal half of the nail is removed, and a longitudinal median incision of the nail bed is carried down to the bone. The nail bed is undermined, and the dorsal tuft is cut with a rongeur. The nail bed is sutured and reversed tie-over sutures are put in the folds and tied over the plantar aspect of the toe. In Zook's technique, successful treatment of pincer nail involves removing the tubed nail to visualize the nail bed. The paronychium is then freed from the periosteum of the distal phalanx through an incision on the tip at the distal end of the paronychium. Fine scissors are used to free the paronychium from the periosteum proximally to beyond the nail fold allowing the nail bed to flatten. A strip of dermis of adequate volume (at least 1 cm in width) is then pulled beneath the paronychium. Management by desiccation and curettage or surgical excision are usually successful, but permanent nail atrophy may occur. A course of systemic retinoids should be considered despite possible recurrence. One milligram etretinate/kg bodyweight may produce a rapid response with resolution of pain and marked reduction of the lesion, including improvement of the bony alterations and nail deformity. Management of subungual KA ranges from conservative local excision to amputation, but aggressive ablative surgery as the initial intervention for this benign condition has probably occurred due to either misdiagnosis or misinterpretation of the nature of the pathology. The treatment of choice is removal of the entire tumour and Mohs' micrographic surgery has been advocated. The patient should then be followed for an adequate period of time to rule out a recurrence. Retinoids may be beneficial in KA, sometimes combined with surgical removal. Eruptive KAs have responded to oral etretinate 1 mg/kg per day with complete resolution. Recurrence can occur after cessation of treatment, requiring maintenance therapy (10 mg on alternative days); however, this mode of treatment is more effective as prophylaxis in multiple KA. 5-fluorouracil has also been used either injected into the lesion, or applied as a 20% ointment three times daily for 3–4 weeks. Intralesional bleomycin may be tried in the distal nail area; as well as methotrexate. With the exception of mild disorders such as '20-nail-dystrophy' (which may pertain to lichen planus), treating the nail dystrophy resulting from lichen planus to prevent severe and sometimes permanent lesions, such as pterygium and onychatrophy, is highly recommended. An intralesional long-acting steroid should be used in the same manner as for treating psoriatic nails. If more than one or two digits are affected and there is no medical contraindication, triamcinolone acetonide is injected intramuscularly (80 mg the first month, then 40 mg monthly for 6 months). The frequency of the injections should be adjusted to the patient's response. Treatment may last for 18 months to 2 years. Retinoids (etretinate or acitretin) are effective before the scarring stage. Azathioprine 100 mg/d has been suggested. Longitudinal linear pigmentation of the nail in persons with fair complexion may be perplexing to the physician and distressing for the adult patient. Complete excisional biopsy is recommended for both diagnosis and treatment. The appropriate technique depends on three factors: (i) the width of the band; (ii) the matrix melanin production site; and (iii) the anatomical location of the band on the nail plate. Longitudinal melanonychia with periungual pigmentation, nail dystrophy, ulceration or a mass that bleeds easily should be treated, a priori, as a malignant melanoma. The technique used for treating racquet nail may be adequate. Macrodactyly, more frequently reported on the hands than on the feet, may be treated with shortening of the enlarged digits coupled with a free nail graft. An excision of an en-bloc crescent-shaped full thickness skin, 3 mm at its greatest width and extending from one lateral nail fold to the other, increases the length of the nail plate. Sonnex et al. (1982) used liquid nitrogen cryosurgery with an 86% cure rate. The field treated included the cyst and the adjacent proximal area to the transverse skin creases overlying the terminal joint. Two freeze/thaw cycles were carried out, each freeze time being 30 s after the ice field had formed, the intervening thaw times being at least 4 min; if this method is adopted then longer freeze times must be avoided or permanent matrix damage may occur. Nail fold excision for distal lesions of the posterior nail fold has been advocated. The injection of a sclerosing agent, such as 1% sodium tetradecyl sulphate (Sotradecol*) into mucoid pseudocysts may well have superseded the previous treatments. After the cyst has been pierced and its jelly-like material expressed, 0.10–0.20 mL is injected, painlessly. One single procedure may be enough. A second or a third one can be performed at 1 month intervals. Adverse reactions such as permanent nail dystrophy have been reported. The careful extirpation of the lesion has been recommended. A drop of methylene blue solution, mixed with fresh hydrogen peroxide, is injected into the distal interphalangeal joint at the volar joint crease. The joint will accept only 0.1–0.2 mL of dye. This clearly identifies the pedicle connecting the joint to the cyst and the cyst itself, which may look like a subcutaneous teno-arthro-synovial 'hernia'. This procedure sometimes also reveals occult satellite cysts. Recently, the importance of removing the osteophytes was stressed; identical success rates were found with osteophytectomy with and without removal of the cystic lesion. Nail deformities resolved in more than two-thirds of cases. Complications following resection of myxoid pseudocysts are mainly joint stiffness, loss of residual motion, persistent swelling, pain, deviation of the distal interphalangeal joint and infection. Nails may split lengthwise or laterally into layers. This occurs mostly in persons who have an occupation involving exposure to moisture. Avoid repeated immersions in soap and water. Follow each hydration by application of an ointment to retain the moisture in the nail plate. Use Cetaphil® as an alternative to excessive exposure to water. Keep the nails short. Oral iron for 6 months, even in the absence of overt anaemia, may be helpful, as well as biotin (10 mg/d). Nail polish is protective, but only oily removers should be used. Nail wrapping limited to the distal portion of the nail may afford protection and camouflage in recalcitrant fragility of the nail keratin. The nail is thickened and distorted in this disorder, often resembling a ram's horn in the elderly. Conservative treatment is indicated, especially in high-risk patients. Fungal infection has to be ruled out. The nail should be trimmed at regular intervals with rotating grinders. Should radical treatment be needed, phenol cautery is superior to cold steel surgery for matricectomy. In this condition, separation of the nail plate starts distally and spreads toward the proximal edge. Whatever the cause, some rules are mandatory. Thorough clipping away of as much detached nail as possible, repeated at 2-week intervals. Gentle brushing with plain soap and water once daily, followed by careful rinsing and drying. Depending on the cause of the complaint (e.g. fungal organisms, psoriasis, impaired peripheral circulation), appropriate local treatment, systemic treatment or both, is prescribed; in all cases, dryness of the onycholytic areas should be maintained. Fungi gain initial entry into a nail by four main routes: (i) via the lateral nail groove and the distal subungual area; (ii) via the dorsal aspect of the nail; (iii) via the undersurface of the proximal nail folds, which remain normal in dermatophytic invasion or become swollen (chronic paronychia), as, for example, in Candida or Fusarium infection; and (iv) endonyx infection is a variant of the distal lateral subungual onychomycosis. Before initiating treatment, potassium hydroxide examination and mycological culture are essential. Sometimes, however, isolation of fungi is difficult (in proximal white subungual onychomycosis) or the problem is compounded if the patient has already received topical or systemic treatment. Pieces of nail (from simple trimming, including some of hyponychium, or 4-mm punch biopsy) should be sent to the pathologist, the hyphae being stained by periodic acid-Schiff. It is possible to achieve a cure using topical therapy alone, with the antifungal nail lacquers ciclopirox or amorolfine, which act as transungual drug delivery systems providing the proximal third of the nail plate is spared. These success rates can be increased by associating a nail lacquer with the systemic treatment. Terbinafine the first fungicidal oral drug is administered at the dosage of 250 mg daily or for 6 weeks in fingernail onychomycosis and 3–6 months for toenails. Itraconazole is administered as intermittent therapy at the dosage of 400 mg daily for 1 week a month (two 'pulses' in fingernail onychomycosis and three or four 'pulses' for toenails). To improve the results, combination therapy using systemic antifungals and nail lacquer drugs should be advised. Moreover, an adjunct to antifungal chemotherapy should be used to remove as much nail material bearing fungi as possible. The following techniques are recommended. Forty per cent urea paste can be applied under an occlusive dressing after thorough protection of the surrounding skin. Softening of the diseased portion of the nail permits its atraumatic separation from adjacent tissue after 1 week. Partial surgical nail avulsion is suitable for onychomycosis of limited extent. Like the previous technique, it results in reasonable remission rates and reduces the time needed for systemic therapy by 50%. Partial surgical avulsion is also advisable in Candida paronychia with secondary nail plate invasion as well in mould paronychia. Recurrences and reinfection are not uncommon (up to 20% of cured patients). They may be prevented by the regular application of topical antifungals on the previously affected nails, soles and toewebs, and fortnightly application of a nail lacquer. The nail splits laterally into layers (see Nail fragility syndrome). These psoriasiform nail lesions are usually limited to one digit in a child and improve spontaneously with time. Topical steroids may be used for limited periods. Infection of the nail folds is characterized by inflammation, swelling and abscess formation. It can be either acute or chronic. If this disorder does not respond to penicillinase-fast antibiotics within 48 h, it should be treated surgically by removing the base of the nail plate, whose proximal third is transversally cut with a nail splitter. In distal subungual infection, probing determines the most painful area and provides an indication for the site of fenestration of the nail plate. Chronic paronychia represents an inflammatory reaction of the proximal nail fold to irritants or allergens. Secondary colonization with Candida albicans and/or bacteria occurs in most cases. Patients should be instructed to follow the same rules described for nail fragility. Nystatin-triamcinolone acetonide ointment (Mycolog®) should be applied two or three times daily until the cuticle has regrown. Monthly injections of triamcinolone acetonide suspension (2.5 mg/mL) into affected nail folds facilitate resolution of the paronychia. In systemic treatment: (i) steroids (methylprednisone 20 mg/d for a few days) can be prescribed in severe polydactylous cases to obtain fast relief of inflammation and pain, and (ii) antifunguals are usually unnecessary; however, fluconazole 50 mg/d has given good results. Conditions that do not respond to medical therapy (e.g. a foreign body) should be treated by excising a crescent-shaped, full-thickness piece of the proximal nail fold, including its swollen portion. Complete healing by granulation takes about 6–8 weeks. Treatment of nail changes in psoriasis is tedious and sometimes unsatisfactory. Nail polish should be used to hide discrete nail changes. Some patients get better spontaneously, and others improve when the associated skin lesions are treated. Potent topical corticosteroids are helpful in treating the dorsal aspect of the proximal nail. Although the efficacy of topical corticosteroids can be enhanced by overnight occlusion, this technique should be used only for limited periods. An intralesional long-acting steroid is injected into the proximal nail fold or into the subungual affected area, using triamcinolone acetonide (Kenalog-10), diluted to 2.5 mg/mL, at a dose of 0.2–0.5 mL per nail. Injections should be repeated monthly for 6 months, then every 6 weeks for the next 6 months, and finally every 2 months for 6–12 months. A digital block is useful to make the treatment less painful, but when several digits are involved, a wrist block may be the appropriate anaesthesia. With the exception of acropustulosis, in which the treatment is consistently effective, variable responses to etretinate are found in nail psoriasis. This vascular post-traumatic tumour is easily removed by surgical shaving (for the pathologist to examine) under local anaesthesia. Haemostasis is achieved with aluminium chloride. The aesthetic appearance of racquet thumb may be improved by narrowing the nail plate and creating lateral nail folds when necessary. The technique used for lateral-longitudinal nail biopsy is performed on both sides of the thumbnail. Back stitches recreate lateral nail folds. Subungual areas of normal fingernails of patients with scabies rarely contain mites. Conversely, Norwegian scabies presents with numerous mites. Treatment of the subungual regions with lindane or other scabicides is recommended in all patients with scabies. Subungual splinters are a form of nail trauma that can be easily and quickly treated by dermatologists. Wood splinters not only cause pain, but are a portal for infectious organisms. Forceps extraction can be attempted by tugging in the direction opposite to that of the entry. Additionally, a local digital block may be followed by a V-shaped cut with a nail splitter, elevation with a nail elevator, and removal of the splinter. A no. 15 blade or a carbon dioxide laser can also be used to remove the overlying nail prior to splinter removal. Treatment with the carbon dioxide laser may obviate the need for a tourniquet by controlling bleeding. This condition, characterized by nail roughness, can be idiopathic or associated with alopecia areata, lichen planus and, less often, psoriasis. The nail changes usually regress spontaneously in a few years. No treatment is required. Recently, biotin oral administration for 6 months has been advocated. A beneficial response following a short course of topically applied 5% 5-fluorouracil is anecdotal. Intralesional long-acting steroids are helpful and recovery is observed within 2–3 weeks. Recurrences of warts are frequent and are not related to treatment. A spontaneous or 'magic' cure is by no means unusual. Liquid nitrogen is often used. To minimize the throbbing pain produced by the frozen lesion, pretreatment application of clobetasol propionate under Blenderm* reduces the inflammatory response to the freeze. Massages with this steroid may be continued twice daily for 3 days. Oral aspirin, 600 mg three times daily, beginning 2 h before and for 3 days after treatment, is also helpful. Shelley and Shelley obtained elimination of 92% of a random series of 258 warts after a single treatment with a multiple puncture technique under local anaesthesia with a bifurcated vaccination needle to introduce bleomycin sulphate (1 µg/mL) sterile saline solution into warts. Imiquimod may well be one of the best local treatment despite its cost. Periungual and subungual warts respond well to carbon dioxide laser treatment under local anaesthesia. Vitamin E at dosages ranging from 600 to 1200 IU daily can induce complete clearing of the nail changes. Itraconazole pulse therapy combined with vitamin E suggest a positive effect of this treatment on nail growth. Total resolution of yellow nails and lymphoedema was observed following oral zinc supplementation for 2 years. In a patient with YNS associated with rheumatoid arthritis, the nail abnormalities completely regressed after gold therapy for arthritis. Treatment of pulmonary tuberculosis cured a patient with YNS. Treatment of associated malignancy may improve the YNS. Topical vitamin E solution in dimethyl sulphoxide applied twice a day has been shown to be successful in the treatment of nail changes in YNS. Intradermal triamcinolone injections in the proximal nail matrix may be useful.