ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

Health Significance Of The Clinical Examinations And Laboratory Investigations Of Skin Disorders

Updated on February 18, 2014

The Skin

Source

Skin Manifestations

The skin is the largest organ in the body and constitutes 15% of the body weight. The skin closely reflects disorders occurring in the internal organ systems and several cutaneous disorders have systemic components. Skin disorders are widespread in developing countries (especially in the tropics, like India). Clinical examination of a dermatological lesion is not complete without a full systemic examination and investigations. Dermatological examination should be performed under conditions of proper lighting.

Points to be stressed in the history: Particular emphasis should be laid on evolutions of the lesion, associated symptoms like itching, pain, fever, etc and the effect of all forms of previous treatment.

Primary Skin Manifestations

Macules: They are flat lesions which are neither raised nor depressed from the surrounding normal skin but showing colour changes. They do not show textural alteration.

Papules: These are circumscribed solid elevations situated superficially on the skin, varying in size from 1mm to 1cm in size, eg, verrucase or warts, lichen planus, popular rash.

Nodules: These are circumscribed solid lesions larger than 1cm in diameter situated deeper than papules in the skin or subcutaneous tissue, eg, erythema nodosum, lupus vulgaris, tertiary syphilis.

Tumours: These are lesions, usually larger and more deeply situated than nodules, e..g., neurofibromata, epitheliomata.

Wheals: These are soft pinkish or whitish evanescent swellings of varying sizes seen specifically in urticaria, e.g. insect bite, angioedema.

Vesicles and bullae: Vesicles are circumscribed collections of free fluid within the layers of the skin. Eg, chickenpox, herpes simplex, herpes zoster. Bullae are collections of fluid larger than vesicles, e.g pemphigus vulgaris, erythema multiforme, burns.

Pustules: These are thin walled superficial collections of pus, eg, small pox, pustular psoriasis.

Crusts (Scabs): These are formed of dried up serum, blood or pus or a combination of these.

Ulcer: This results from loss or destruction of superficial tissue which may involve the epidermis and part of the dermis (e.g ecthyma) or deep subcutaneous tissue (e.g necrotic ulcers, stasis ulcers).

Lichenification: The normal wrinkles of the skin become prominent and they enclose flat-topped, hyperpigmented papules which may also show mild scalling, eg, lichen simplex chronicus, neurodermatitis, Lichenfication results from constant irritation such as rubbing or scratching.

Pigmentary Changes:Hyperpigmentation may be seen following acute or chronic inflammatory skin diseases. Sometimes, dark-skinned races may react with hypopigmentation instead of hyperpigmentation.

Excoriation: This is loss of epidermis brought about by scratching.

Atrophy: Atrophy of the skin manifests as bypopigmented, wrinkled areas. The connective tissue in the dermis is involved mostly. The dermal appendages and subcutaneous tissues are also lost.

Slcerosis: The dermis and subcutaneous tissue are indurated. The uverlying epidermis is thinned out, eg, scleroderma.

Skin Biopsy

Source

Laboratory Investigations

A full dermatological diagnosis may necessitate several investigations.

General investigations: In many diseases, like diabetes, jaundice and acanthosis nigricans, full systemic investigations are necessary for diagnosing the systemic illness.

Special investigations:

  1. Biopsy
  2. Scarping of scales and examination for fungal infection: The scales are suspended in 20% potassium hydroxide which dissolves keratin, but no fungal filaments and spores, and examined under the miscroscope.
  3. Culture of material for bacteria and fungi in appropriate media.
  4. Dark- field examination of serum from ulcers on genitalia and skin or mucous surfaces for spirochetes.
  5. Skin slit scrapings are done to demonstrate M. Leprae. Smears are made from the dermis through a small slit in the skin, using a scalpel and the material is stained for AFB. This method can be used for diagnosing onchocerciasis and cutaneous leishmaniasis.
  6. Microscopic examination of scraped material from skin lesions may reveal parasites like sarcoptes scabei.

Skin tests for detecting allergy

Patch test: These tests are used in detecting the allergen involved in a suspected case of contact allergic dermatitis.

Photo-patch test: This is used to detect allergens which cause contact photosensitivity.

Intradermal tests: The antigen is introduced intradermally in low concentration. These are particularly useful for testing drug and food allergy. Other tests such as “prick test” and “scratch test” are used in detecting the allergen in food or drug allergy. The suspected substance is applied as a solution on the surface of the skin and it is allowed entry through small pricks or scratches.

© 2014 Funom Theophilus Makama

Comments

    0 of 8192 characters used
    Post Comment

    No comments yet.

    working

    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, hubpages.com uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at: https://hubpages.com/privacy-policy#gdpr

    Show Details
    Necessary
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the googleapis.com or gstatic.com domains, for performance and efficiency reasons. (Privacy Policy)
    Features
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Marketing
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Statistics
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)