Diabetes is a common condition that is increasing in incidence worldwide. Although the skin manifestations of this condition are well described, there is scant literature on the associated nail changes. In this review, we describe the various clinical features of nail changes associated with diabetes, which can be broadly divided into infections, vascular changes, neuropathic manifestations and miscellaneous changes, although there is overlap between them. There is no pathognomonic nail alteration, but it is important for clinicians to be aware of the potential nail manifestations in diabetes as they can facilitate investigations and thereby early diagnosis of diabetes, resulting in holistic management of the patient.

Diseases of the skin, hair, nails and mucosa can appear as flesh-colored lesions or may present as any of the colors of the visual spectrum. Diseases associated with blue (or shades of blue) discoloration represent a unique group of conditions that occur de novo or as a reaction to either a topical or a systemic agent to which the individual has been exposed. Blue diseases can affect the skin, the nails or the mucosal membranes of the mouth (buccal mucosa, gingiva, lips, palate or tongue) or eyes (sclera). In addition to appearing blue, they can also appear as blue-black, blue-brown, blue-gray, blue-green, blue-purple, blue-red, and blue-silver. The conditions range from those secondary to exogenous agents (systemic or tattoo or topical) to syndromes to systemic diseases to tumors (adnexal, melanocytic, vascular, or miscellaneous). A comprehensive attempt to include all conditions that have been described as blue (or a shade of blue) has been performed by evaluating the following terms using the medical search engine PubMed: blue and either gingiva, lips, lunula, mucosa, nails, oral, palate, sclera, skin, or tongue. Subsequently, the conditions were organized by color (blue and shades of blue) and within each color by location (skin, nails, oral mucosa and sclera). The results are presented in organized tables; in addition, there is discussion of some of the conditions that are unique to one or more specific locations. In conclusion, 'preserve and cherish the pale blue dot' and remember that a big red rock eater with chrysiasis is the answer to the riddle, "What is big and blue and eats rocks?"

In this study, cutaneous toxicities associated with the administration of chemotherapy in combination are discussed. Rapidly growing cells are the targets of chemotherapy, so the skin, hair follicles, and nail matrix are frequently affected by chemotherapy. Chemotherapy skin reactions are more likely toxic than allergic reactions. There are numerous chemotherapy-induced cutaneous reactions that have been described in the literature. In addition to a variety of miscellaneous reactions, 19 major cutaneous reactions were discussed in current study. This study was designed to evaluate the clinical spectrum of all cutaneous toxicities over two years in hospitalized and ambulatory patients in the Department of Pediatric oncology and to establish probable relationship between the reaction and suspected anticancer protocol with the help of WHO (World Health Organization) Common Toxicity Criteria by Grade. The data on the cutaneous toxicities were analyzed by percentile and ranking method. The minimal (0.8%) cutaneous adverse effects monitored during the study were Petechiae, photosensitivity, pruritus, urticaria, wound-infection, erythema multiforme, hand-foot skin reaction, injection site reaction, dry skin. Alopecia was the single most common (64.3%) adverse effect observed during the study, where as the pigmentary changes were the second most common (18.2%) adverse effect monitored. While these side effects are generally not life threatening, they can be a source of significant distress to patients, especially alopecia.

All structures of the skin may be affected by side effects of antineoplastic chemotherapy. The most commonly described effects concern skin adnexes, especially hair with alopecia. Nails are also frequently involved. Eccrine sweat or sebaceous gland involvement is more rarely reported. Mucous membranes, particularly in the mouth, are frequently altered by several mechanisms; direct cytotoxicity, infection, and a decrease in polymorphonuclear or platelet counts. Among cutaneous side effects, hyperpigmentation is very common and may have different clinical patterns; generalised, figurated, or localised. Acral erythema is another cutaneous side effect that is relatively specific to chemotherapy and is often dose-related. Some cutaneous side effects are related to an interaction between chemotherapy and radiation, particularly phototoxicity, recall phenomenon, and radiation enhancement. Miscellaneous, less frequent, side effects are described; sclerodermiform dermatitis, Raynaud's phenomenon, and hypersensitivity syndrome. In some cases, cutaneous side effects are relatively specific to one type of drug. Capillary leak syndrome is most often related to taxanes. Hydroxyurea is responsible for some peculiar cutaneous side effects (ulcerations, pseudo-dermatomyositis), perhaps due to long-term administration of the drug. Although mucocutaneous side effects of chemotherapy are frequent and sometimes severe, interruption of the culprit drug is rarely mandatory. However, adaptation of the dosage or prevention of some of these side effects remains necessary. Antineoplastic chemotherapies are widely used in many therapeutic protocols and may be responsible for numerous mucocutaneous side effects, either specific or more unusual. In rare cases, the severity of these side effects may require interruption of therapy. They may involve skin adnexes, mucous membranes or the skin itself. This review discusses cytotoxic antineoplastic drugs only, not cytokines, monoclonal antibodies or transduction factors used in the treatment of cancer.

The population groups predisposed to onychomycosis and factors associated with a poor response to antifungal therapy may be subdivided into (a) genetic, (b) environmental, (c) systemic conditions, (d) local nail characteristics, and (e) other miscellaneous items. By paying attention to the scenarios that may lead to a suboptimal response to the therapy and a higher probability of relapse of the onychomycosis, it may be possible to improve the overall cost-effectiveness of treatments for onychomycosis. Besides attempting to achieve a cure when treating onychomycosis it is important to take steps to prevent reinfection with fungal organisms.

A variety of individual nail dystrophies that are not categorized easily in other articles are reviewed. Onychoatrophia, anonychia, onychorrhexis, leukonychia, Beau's lines, onycholysis, onychomadesis, onychoschizia, haplonychia, longitudinal melanonychia, and ventral pterygium are included and pictured clinically. Their clinical description, etiology, associated conditions, differential diagnoses, and treatments are discussed and tabulated.

Leprosy can cause many nail changes, which have been observed in up to 64% of infected patients. The manifestations of leprosy (clinical, bacteriologic, and histological) are profoundly affected by the patient's immunological status, which also determines the prognosis. Nail changes in leprosy can be caused by neuropathy and trauma, vascular impairment, infections, and miscellaneous changes. Often more than one factor will be important. Paradoxically, nail changes in tuberculoid and lepromatous patients are similar, despite wide differences in pathology. This may be because etiological factors common to both are implicated. Factors only associated with lepromatous disease are invasion of the bones of terminal phalanges by lepromatous granulomas and endarteritis occurring during type 2 lepra reactions. Otherwise, the only difference from tuberculoid leprosy is the time of onset and the symmetry of lesions. Lepromatous patients develop nail changes late in the course of disease. The presentation is usually bilaterally symmetrical. However, these changes are not specific to leprosy, and may be observed in other peripheral neuropathies.

The anatomy and physiology of the perionychium are reviewed and complications secondary to trauma, to miscellaneous problems (such as neuroma, infections, and cysts), and to tumors are discussed.

Systemic drugs or ingestants may affect the nails. Changes vary from asymptomatic growth rate changes and pigmentation abnormalities to nail shedding and permanent deformity. The former two changes are most common. Presented are changes in nails caused by antibiotics, cancer chemotherapeutic drugs, poisons and ingestants, antimalarial drugs, and miscellaneous drugs.

Nails can act as a barometer of an individual's health, offer clues to nutritional disturbances and serve as windows through which to view capillary changes associated with constitutional disease. Understanding growth and development of normal nails is essential to the identification and interpretation of nail pathology. Causes of onychopathology include genetic disease, trauma, tumors, dermatologic disease, miscellaneous acquired disorders and generalized systemic disease. Diagnosis is aided by the realization that the nails have a limited number of reaction patterns when disturbed by disease. Any of these reactions may manifest a host of disorders. Clinicians should remember to include the nails in patient assessment. The nails are interesting anatomical and physiological areas that can help make a diagnosis.

Subungueal splinter hemorrhage (S.U.S.H.) has been reported in various conditions and may herald a serious systemic disease. It has been related to miscellaneous conditions such as: subacute bacterial endocarditis, severe rheumatoid arthritis, uninfected mitral stenosis, trichinosis, peptic ulcer, hypertension, neoplasm, trauma, and in some cases, is considered idiopathic. Some dermatologic conditions such as psoriasis, dermatitis, and fungal infections may also produce S.U.S.H. It consists of "a homogeneous mass of blood in a layer of squamous cells, adherent to the under surface of the nail, considered to be of embolic origin." In a brief review of pertinent medical literature on thromboangiitis obliterans, we were unable to find a description of its occurrence in this disease. The earliest lesions described in this condition are "painful vesicles on the pulp of digits with intense hyperemia and hypersensitivity of the surrounding skin." It is our opinion that S.U.S.H. is an earlier and quite useful sign of arterial involvement as seen in the following cases observed in our vascular disease section.