Causes of longitudinal nail splitting: a retrospective 56-case series with clinical pathological correlation

BACKGROUND

Split nail (SN) is a rare type of nail fragility syndrome, characterized by a longitudinal fissure involving the entire thickness of the nail plate. Longitudinal nail splitting may be caused by direct injury to the nail plate or matrix insult. Few articles have been published on the topic, most were related to the traumatic aetiology. Some case reports mention tumours and inflammatory disorders as other causes.

OBJECTIVES AND METHODS

The aim of this retrospective study was to analyse the clinical and histopathological features of 56 SN collected at the nail consultation of the dermatology department at Saint Pierre University Hospital in Brussels, between 1997 and 2019.

RESULTS

Fifty-six patients were included (34 women and 22 men) with median age of 44.2 years. The fingernails were 3.2 times more frequently affected than toenails, especially the thumb. The most frequent aetiologies were tumours (45.6%), inflammatory diseases (26.3%) and traumas (19.3%). Congenital (5.3%) and systemic disorders (3.5%) were rarer causes. Histopathological slide review confirmed that alteration of the nail matrix integrity causes split nail, resulting either from matrix stretching by an underlying tumour or from impairment of the keratinization process by inflammatory diseases, melanocytic tumours and Bowen's disease.

CONCLUSIONS

This study is the largest case series of longitudinal nail splitting to date. It is the first to gather nail disorders causing SN with their clinical pathological correlation. The most common causes are traumatisms, tumours and inflammatory disorders. Congenital and systemic disorders are rarer. Tumours are responsible for half of the cases from which one third are malignant, mainly melanoma. When facing a monodactylic SN, benign as well as malignant tumours should be ruled out before concluding to traumatic aetiology.

European recommendations for management of immune checkpoint inhibitors-derived dermatologic adverse events. The EADV task force 'Dermatology for cancer patients' position statement

The introduction of immune checkpoint inhibitors (ICIs) opened a new era in oncologic therapy. The favourable profile of ICIs in terms of efficacy and safety can be overshadowed by the development of immune-related adverse events (irAEs). Dermatologic irAEs (dirAEs) appear in about 40% of patients undergoing immunotherapy and mainly include maculopapular, psoriasiform, lichenoid and eczematous rashes, auto-immune bullous disorders, pigmentary disorders, pruritus, oral mucosal lesions, hair and nail changes, as well as a few rare and potentially life-threatening toxicities. The EADV task force Dermatology for Cancer Patients merged the clinical experience of the so-far published data, incorporated the quantitative and qualitative characteristics of each specific dirAEs, and released dermatology-derived, phenotype-specific treatment recommendations for cutaneous toxicities (including levels of evidence and grades of recommendation). The basic principle of management is that the interventions should be tailored to serve the equilibrium between patients' relief from the symptoms and signs of skin toxicity and the preservation of an unimpeded oncologic treatment.

The importance of skin manifestations, serology and nailfold (video)capillaroscopy in morphea and systemic sclerosis: current understanding and new insights

Since the field around morphea and systemic sclerosis (SSc) is evolving rapidly, this review approaches conventional as well as more recent clinical developments from a dermatological point of view. Skin manifestations are critical in sub-classifying these diseases ensuring a correct prognosis for these patients. They can be discretely present, and therefore, diagnosis can be challenging sometimes, implicating a thorough dermatological examination is mandatory. Furthermore, a growing amount of dermatologists perform nailfold videocapillaroscopy (NVC), a more recent reliable non-invasive imaging technique used for in vivo assessment of the microcirculation at the nailfold. After all, specific NVC-changes are present in a majority of patients with SSc. This way, dermatologists not only take part in the diagnosis process through clinical investigation but also through the use of a modern state of the art imaging technique that is becoming the golden standard in SSc multidisciplinary workup. In this review, current understandings for NVC in morphea and SSc are revised. So far, the role of NVC in the diagnosis/prognosis/classification of morphea patients has not been thoroughly investigated to make proper conclusions. As for SSc, it is well known that NVC contributes to the diagnosis and can make a fundamental difference especially when obvious clinical SSc signs are absent. This review emphasizes the (somewhat underestimated) role of dermatologists in the process of diagnosis and follow-up, and thus, the difference we can make for our patients and fellow colleagues in the multidisciplinary workup of SSc and morphea.

[Management of non melanoma skin cancer by the general practitioner]

The incidence of skin cancer cases has increased significantly during the last decades. Non melanoma skin cancer (NMSC) is the most common cancer in Caucasian populations. This term refers to 2 major types of skin cancer : basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). Mortality from BCC and SCC is low but there may be substantial morbidity from disfigurement as these lesions tend to be located on the skin of the head and neck. Actinic keratosis is a premalignant condition that may evolve into SCC. Fortunately, skin cancer is amenable to early detection and potential cure. General practitioners may play a very important role in the timely diagnosis and management of these tumors. They are on the front line to detect NMSC : opportune examination coupled with good observation skills allow a high detection rate of suspicious lesions. It is essential to identify the high-risk patient as well as the clinical signs of suspicious lesions. This article outlines the clinical features of common NMSC and highlights which lesions should be best referred to a dermatologist.

[Skin sampling for the general practitioner]

Skin samplings are easily performed in general practice. They include skin biopsies, nail clippings, skin scrappings, hair pluckings as well as trichograms. The different types of skin biopsies are curetage, shaving, punch and elliptic biopsies. They are most commonly used for the diagnosis of inflammatory skin conditions and cutaneous tumors. The biopsies are performed under local anesthesia and each has specific indications. Their complications are minimal. In order to obtain as much information as possible the lesion to be biopsied should be judiciously selected, harvested without being harmed and sent to a skin-oriented pathologist. Nail clippings, skin scrapings and hair plucking allow diagnosis of superficial skin mycosis (tinea, pityriasis versicolor) and are mandatory before prescribing systemic treatment. Scrapping of an itch mite burrow may sometimes reveal the sarcopte. Trichogram may be useful in the work up of a hair loss.

[Superficial acral fibromyxoma in a sub-matricial location: An unusual variant]

BACKGROUND

Superficial acral fibromyxoma (SAFM) is a benign soft tissue tumor located in the acral areas, particularly the peri- and sub-ungueal areas. Sub-matricial localisations have not been reported to date.

PATIENTS AND METHODS

We report herein the clinical and pathological presentation of three cases of SAFM located solely under the matrix. The patients presented with pseudo-clubbing, onychogryphosis or triangular macrolunula. The histopathological appearance was characteristic.

DISCUSSION

SAFM is a slow-growing, skin-colored, firm nodule, located chiefly on the digits or the toes, and especially in the nail area. It may or may not be painful. Microscopically, it presents as a relatively well-circumscribed but unencapsulated dermal tumor, composed of spindle shaped cells integrated in a myxocollagenic matrix, sometimes invading the subcutis. Tumor cells diffusely express CD34. A conservative surgical approach is recommended. Both clinicians and pathologists should be aware of this entity in order to avoid misdiagnosis, which can lead to unwarranted mutilating surgery.

CONCLUSION

Sub-matricial localisation of SAFM is extremely rare and may present as pseudo-clubbing, isolated onychogryphosis or a triangular macrolunula. A conservative surgical approach should be recommended.

[Differential diagnosis of onychomycosis]

Almost 50% of nail pathology is caused by onychomycosis. However, the nail has a limited reservoir of clinical expressions and many conditions may mimic onychomycosis. Its differential diagnosis should be known in order to avoid useless or even toxic treatments. When confronted with ungual alterations restricted to one or some nails, it is fair to evoke onychomycosis but one should keep in mind repeated traumata to the toenails, psoriasis and chronic paronychia on the fingernails. Involvement of a large number of nails, especially all twenty nails, should not first suggest a fungal infection but rather an inflammatory or systemic condition. It is mandatory to always sample the nail for mycological examination before prescribing any systemic treatment.

Periungual and subungual pyogenic granuloma

BACKGROUND

Nail pyogenic granuloma (PG) is common, often seen as an urgent case, given the recent onset as a bleeding nodule. Nail PGs are due to different causes that act through different pathogenetic mechanisms and may be treated in several ways. Both causes and treatments of nail PG have never been classified.

OBJECTIVES

To classify nail PG according to the pathogenesis, describe the clinical and pathological features and provide guidelines for a correct diagnosis and treatment.

METHODS

A retrospective, observational study was performed reviewing epidemiological and clinical features of 58 cases of PG seen at our Departments in the last 5 years. A review of the literature was also carried out, using PubMed database and dermatological textbooks.

RESULTS

Nail PG is usually due to the following causes: drugs, local trauma and peripheral nerve injury. Histopathology shows similar features in every type of PG, irrespective of cause and location.

CONCLUSIONS

The localization of nail PG, the number of digits involved and clinical history help to identify the cause. When PG is single, especially if it involves the nail bed, histological examination is necessary to rule out malignant melanoma. Treatment must be chosen according to the underlying cause.

[Ingrown nail: A new cause of chronic perionyxis]

BACKGROUND

Retronychia is the phenomenon of ingrown nail resulting in inflammation of the proximal subungual fold and is a newly described entity. Herein, we report a new case revealed through chronic proximal perionyxis.

PATIENTS AND METHODS

A 52-year-old woman followed up for hypothyroidism, for which she was receiving treatment, consulted for pain in the lateral fold of the left big toe that had been ongoing for four months and for which glomic tumour was the suspected cause. Questioning revealed repeated microtrauma due to wearing of tight shoes and lack of growth of the toenail over the previous four months (in contrast with the contralateral toenail). Examination showed painful proximal perionyxis of the left big toe, with discharge from the subungual fold. Ultrasound examination of the subungual fold revealed effusion of fluid around the matrix, and this was confirmed by MRI. Surgical avulsion of the nail was carried out, and recovery was complete.

DISCUSSION

Retronychia is the result of a loss of continuity between the nail plate and the nail matrix, generally as a result of mechanical factors (distal trauma). However, unlike onychomadesis or Beau's lines, there is a disturbance of alignment between the two parts of the nail, which is normally maintained by the proximal subungual fold. This prevents newly formed nail from progressing towards the distal part of the plate, which itself is pushed into the nail bed and forced towards the proximal fold, causing inflammation of the latter structure. In our case, the pain recorded in the lateral fold was misleading, hence the ultimately unnecessary use of MRI to rule out the hypothesis of glomic tumour. Paronychia, discontinuation of nail growth and weeping through the subungual fold all argued in favour of a diagnosis of retronychia, which was confirmed by surgery. Surgical nail removal is the curative treatment for retronychia and results in complete cure without relapse or occurrence.

CONCLUSION

Retronychia should be suspected in the event of persistent proximal perionyxis, particularly in a setting of trauma with interrupted nail growth. Nail avulsion constitutes both a diagnostic and a therapeutic procedure.

[When creams turn into a burden]

Topical treatment is the cornerstone of therapy for patients suffering from psoriasis. Its efficacy and safety have been demonstrated in a large number of publications. However, in daily life, the treatment outcome is often less satisfactory than the results published in the literature. This phenomenon is clearly linked to non-adherence. Indeed, patients with psoriasis frequently consider the topical therapies frequently as a heavy burden. The successful management of psoriasis with topical agents requires a perfect understanding between the patient and the practionner, which provides regular renewal of the patient's motivation.

[Vulvar lichen sclerosus]

Vulvar lichen sclerosus is a frequent mucocutaneous disease especially affecting 50 to 60 year-old women but with a possible onset at very young age. Symptoms are most disabling including pruritus and dyspareunia. Vulvar mucosa gradually becomes more white and atrophied. Degeneration into epidermoid carcinoma is possible. Treatment only consists of topical corticosteroids.

[How I treat...varicosities by sclerotherapy]

Sclerotherapy is a technique for the treatment of varicosities, vascular ectasia, and sometimes, leg varicose veins. This method is aesthetic and in some cases therapeutics and uses sclerosing agents, electrocoagulation and exceptionally LASER. These relatively simple methods are safe and efficient if they are applied with a rigorous procedure by well trained physicians.

Hyperkeratotic nail discoid lupus erythematosus evolving towards systemic lupus erythematosus: therapeutic difficulties

Nail changes occur in about 25% of systemic lupus erythematosus (SLE) cases. Onycholysis has been reported as the most frequent abnormality in SLE. Nailbed hyperkeratosis may be observed in both SLE and discoid lupus erythematosus (DLE). Involvement of the nail apparatus in DLE is extremely uncommon and never restricted to it. We report on a patient in whom the clinical features on the proximal nailfold were similar to those observed on the skin of a patient with typical DLE. This has, to the best of our knowledge, not yet been reported. The patient also exhibited a very distinctive prominent subungual hyperkeratosis. Interestingly, the patient developed biological alterations suggesting a systematization of the disease. Only a combination of systemic corticoids, retinoids and antimalarials was able to achieve nail improvement and this partial resistance to therapy may be explained by the very unusual subungual hyperkeratosis.

Periungual lipoma: About three cases

Lipomas are one of the most common benign soft tissue tumors. The usual development sites are the neck, the torso, and the legs. Lipomas of the nail unit are extremely rare. Only five cases have been reported up to now, four in subungual locations and one in the lateral nail fold. We report three cases of peri-ungual lipomas, one on the digit and two on the toes. Two of them exhibited the histological features of perisudoral lipomas.

[Xanthomas]

Xanthomas are cutaneous lesions due to a local accumulation of spumous cells in the dermal tissue or the tendons. Histologically, they are characterized by the presence of histiocytes, fibroblasts, macrophages and Touton cells full of lipids. Xanthomas may be found on any part of the body and are usually yellow-orange in color. They may or may not be associated to hyperlipoproteinemia which may be genetic or secondary. A blood test and a complete physical examination are necessary in case such a lesion is discovered. When there is no hyperlipemia some types of xanthomas may be associated to rare diseases. Xanthomas are classified according to their clinical features.

[The management of onychomycosis]

Despite the appearance of the new systemic drugs there is still an incompressible failure rate in treating patients affected by onychomycosis. Moreover some patients are unable or unwilling to take oral drugs. They perceive the infection to be too trivial to deserve systemic therapy. In addition the use of the new potent systemic drugs may sometimes be limited by adverse effects and drug-drug interactions. A rationale for a stepped therapeutic approach to the treatment of onychomycosis is suggested using the transungual antifungal delivery systems, the systemic antifungal drugs and surgical or chemical debridement. Long-term management with the nail lacquers applied twice a month should still improve the cure rate and its economic implication.

[Sutures in skin surgery]

Dermatologists performing skin surgery mostly use the square knot. Other underused or even forgotten suturing techniques may still be helpful in some instances. We shall emphasize some simple techniques such as the horizontal mattress suture, the "cross stitch", the "corner stitch" (half buried mattress suture), the buried dermal suture, the buried vertical mattress suture, the continuous mattress suture and the running intradermal suture. In given circumstances, all of them may improve suturing and promote healing. Technical aspects, advantages and disadvantages of each type of suture will be briefly described.

[Green nail syndrome or chloronychia]

"Green nails" or chloronychia is an infection mostly caused by Pseudomonas ueruginosa but also by other bacterial or fungal contamination. The clinical appearance consists in a typical triad: green discoloration of the nail plate associated with proximal chronic paronychia and disto-lateral onycholysis. Exposition to moist environment, microtraumatisms, oaychotillomania and associated nail diseases such as psoriasis may promote infection by Pseudomonas. Treatment consists in cutting of the detached nail plate, brushing the nail bed with a 2% sodium hypochlorite solution twice daily and eviction of the repeated immersions by wearing cotton and latex gloves.