Disorders of the nail apparatus
Aprof.Moh.Yassin Normal nail apparatus is made up of the nail plate & surrounding soft tissue structures -nail plate: the hard protective tool, the product of the nail apparatus. Rest on & is firmly attached to the nail bed, which is attached to underlying bone. -proximal nail fold: covers proximal one-quarter of the nail plate -cuticle: junction of two epithelial surfaces of proximal nail fold, projects distally on to nail surface, sealing proximal nail fold & nail -lateral folds: usually cover lateral edges of the plate -lunula: underlies proximal fold. Normally is white represent most distal region of the matrix -free margin: distal nail. -nail matrix: proximal matrix underlies nail plate to distal border of lunula. Distal matrix is distal to distal border of lunula produces major part of nail plate. -nail bed: consist of epidermal part (ventral matrix) no more than two-three cells thick, & dermis closely apposed to periosteum of distal phalanx. Hyponychium: space under free margin of nail plate from point of separation of nail plate from nail bed to the distal end of the nail plate*function of nails: 1. Provide strength & protection for the terminal phalanx & finger tip from trauma. 2. Helps fine touch & handling small objects. 3. They are unparallel in their abilities, to relieve itching & represent to many people an extension of their esthetic beauty. *nail growth:- Finger nail grow an average of 0.1 mm/day (1cm/3months), requiring about 4-6 months to replace a complete nail plate. - The growth rate is much slower for toe nails, with 12-18 required to replace the great toe nail (1cm/11months).
*physiological & environmental factors affecting the rate of nail growth:
Fasterslower
Daytime pregnancy minor trauma right hand nails Youth Finger Summer middle, ring, index male gender
night time first day of life left hand nails old age toes winter thumb & little female
* Pathological factors affecting the rate of nail growth:
fasterslower
1.Psoriasis 2.pityriasis rubra pilaris 3.etoretinate therapy 4.Idiopathic onycholysis of women 5.Bollous Icthyosiform erythroderma 6.hyperthyroidisim 7.L-dopa 8.A-V shunt
1.finger nail immobilization 2.Fever 3.methotrexate, azathioprine 4.Denervation 5.poor nutrition 6.Kwashiorkor 7.Hypothyroidisim 8.yellow nail syndrome 9.relapsing polychondrit
A/ nail disorders associated with skin disease:
1. Psoriasis: nail changes are characteristic of psoriasis & the nails of patients should be examined. -The incidence of nail involvement in psoriasis varies from 10-50%. Nail involvement simultaneously with skin disease, but may occur as an isolated finding. Over 50% of patients suffer from pain & many are restricted in their daily activities. -pitting: sharply defined ice pick-like depression in the nail plate is the most common finding, other causes of pitting (e.g.: eczema, fungal infection & alopecia areata). -onycholysis: psoriasis of the hyponychium result in the accumulation of yellow, scaly debris that elevates the nail plate, psoriasis of the nail bed causes separation of the nail from the nail bed, separation begin at the distal groove or under the nail plate & may involve several mails. -nail deformity: excessive involvement of the nail matrix results in nail losing its structural integrity resulting in fragmentation & crumbling. -oil spot lesion: psoriasis of the nail bed may cause localized separation of the nail plate, cellular debris & serum accumulates in this space. The brown, yellow color observed through the nail plate looks like a spot of oil.Treatment: -nail psoriasis is difficult to treat, but may respond to different approaches-relapse is common. -nail may improve when patients are treated with systemic agents such as Cyclosporine, Methotrexate or Acitretin. -all local therapies have limitation -Triamcinolane acetonide: intralesional injections at monthly intervals into the matrix (2.5-10mg/ml) -Topical 5u (5flourouracil) is effective. -topical tazoretine, topical calcipotriol, topical anthralin. 2. Lichen planus: the reported incidence of nail involvement in lichen planus varies from less than 1% to 10% Lichen planus may occur without skin changes. -it may occur at any age, most commonly begins during the 5th or 6th decade, and the various nail changes are: *irregular longitudinal grooving & ridging of the nail plate, thinning of nail plate & pterygium formation (adhesion of proximal nail fold to the scarred matrix).
*shedding of the nail plate with atrophy of the nail bed. *subungual keratosis- longitudinal erythronychia (red streaks) - subangual hyper pigmentation *Twenty nail dystrophy (trachyonychia) may be the sole manifestation of lichen planus Treatment: It is mostly unsatisfactory. -intralesional injection of corticosteroids may be of help, digital nerve block should be considered -topical corticosteroid under polyethylene occlusive dressings, are usually inadequate -oral prednisone (0.5-1mg/kg for 3 weeks) or oral retinoid in combination with topical steroids applied to the involve sites have been successful in some patients. 3. Alopecia Areata: a few patients with alopecia areata have shallow pitting or surface stippling in uniform or grid like pattern 4. Daricr's Disease: -subungual hyperkeratosis- fragiling & splintering with longitudinal altern white & red streaks -triangular nicking of the free edges
Pitting of alopecia areata
Darier DiseaseB/Acquired Disorders: -Bacterial & viral infections: 1. Acute paranychia: (inflammatory reaction of the folds surrounding the nails) -the rapid onset of painful, bright red swelling of the proximal & lateral nail fold may occur, spontaneously or may follow trauma or manipulation -superficial infections present with an accumulation of purulent material behind the cuticle -the small abscess is drained by inserting a instrument pain is abruptly relieved. -the bacteria causing acute paronychia are (staph. Aureus, strep. Pyogen, pseudomonas species, proteus species or anaerobes) -the bacteria usually cause acute abscess (staphylococcus), erythema & swelling (streptococcus) & Candida albicans cause chronic swelling 2. Chronic paronychia: is not a yeast infection but rather an inflammation of the proximal nail fold -it evolves slowly & present initially with tenderness & mild swelling about proximal & lateral nail folds -individuals whose hands are repeatedly exposed to moisture (Bakers, dish washers & dentists, house wives) are at greatest risk -the cuticle separates from the nail plate accelerate the process -the nail plate is not infected & maintains its integrity although its surface becomes brown & rippled.
Acute Paronychia
Chronic paronychia
Treatment: -acute paronychia: -acute inflamed pyogenic abscess should be drained -if stains show pyogenic cocci, semi synthetic penicillin or cephalosporin should be given orally. -if these are ineffective, MRSA or mixed anaerobic bacteria should be suspected, agumentin or treatment by sensitivities of cultural organisms will improve the cure. -chronic paronychia: -resolution depends on avoiding exposure to contact irritants. -every attempt should be made to keep proximal nail fold dry -cotton gloves under rubber gloves should be worn in handworkers -While Candida is most commonly recovered organism in chronic paronychia, topical or oral antifungal lead to cure in only about 50% of cases. -if topical steroids are used to decrease inflammation & allow for tissue repair 3. Drug induced paronychia: the protease inhibitors (lumivadine & indinavir used to treat HIV have been reported to cause paronychia) 4. Pseudomonus infection: -repeated exposure to soap & water cause maceration of the hyponychium & softening of the nail plate. -separation of the nail plate (onycholysis) exposes a damp, macerated space between the nail plate & nail bed. -the nail assumes a green-black color. -there is a little discomfort or inflammation. -this may be confused with subungual hematoma, but the absence of pain with pseudomonas infection establishes the diagnosis -apply few drops of mixture of one part chlorine bleach /four parts water under the nail three times a day.
Onycholysis with pseudomonas infection
5. Herpetic whitlow: -dentists & nurses used to be at risk of acquiring herpes simplex infection of the fingertip. -the course similar to herpes simplex in other sites except that the extreme pain from the swollen fingertips. Fungal nail infections: Onychomycosis (Tinea Unguium): onychomycosis is defined as infection of the nail palate by fungus & represent up to 30% of diagnosed superficial fungal infections. Trichophyton. Rubrum accounts for most cases, but many fungi may be causative, Microsporum & Trichophyton & E.floccosum & may also be caused by yeasts & non-dermatophytic molds. There are four classic types of onychomycosis: 1. Distal subungual onychomycosis: primarily involves the hyponychium, with 2ndary involvement of the underside of the nail plate of finger nails & toe nail. Usually caused by T. rubrum White superficial onychomycosis: this is an invasion of the toe nail plate on the surface of the nail it's produced by T. mentagrophytes, species of cephalosporium & aspergillus, & fusarium oxysporum fungi. In the HIV positive population it is caused by T. rubrum. 2. Proximal subungual onychomycosis: involves the nail plate mainly from the proximal nail fold, producing specific clinical picture. It is produced by T.rubrum & T.megninii & may be an indication of HIV infection.3. Candida onychomycosis: produces destruction of the nail & massive nail bed hyperkeratosis. It is due to C.albicans & is seen in patients with chronic mucocutaneous candidiasis. Clinically: .Onychomycosis caused by T.rubrum starts at the distal corner of the nail & involves the junction of the nail & its bed. . A yellowish discoloration occurs which spreads as streak in the nail . Later subungual hyperkeratosis occurs & becomes prominent until the entire nail becomes affected. . Gradually the entire nail becomes brittle & separated from its bed as a result of piling up of subungual keratin Diagnosis: .the demonstration of fungus is made by microscopic examination or by culture. .the submitted clippings or curetting must include dystrophic subngual debris. .immediate examination may be made if very thin shaving or curetting are taken from the diseased nail bed are examine with KOH solution. .histopathological examination with periodic acid Schiff stain (PAS)
Differential diagnosis: Dystrophic nails can be produced by: .psoriasis-lichen planus-eczema-and contact dermatitis .hyperkeratotic (Norwegian) scabies. Treatment: .Topical treatment: Ciclopirox & amorolfine nail lacquers. These agents are modestly effective. .systemic treatment: -Terbinafin (Lamisil): For finger nail in doses of 250mg/day for 6-8 weeks. For toe nails the course for 12-16 weeks -Itraconazole (sporanox): Is generally given as pulsed dosing as 200mg twice daily for one week of each month, for two months when treating finger nails & for 3-4 months when treating toe nails -Fluconazole (Diflucane): At doses of 150-300mg once a week for 6-12 months appear to be effective
Trauma: 1. Onycholysis: the painless separation of the nail from the nail bed is common separation is usually begins at the distal groove & progresses irregularly & proximally. Causing part or most of the plate to become separated. The non adherent portion of the nail is opaque with white, yellow or green tinge Causes of onycholysis: 1-psoriasis 2-trauma 3-candida or pseudomonas infection 4-internal drugs 5-puva 6-contact with chemicals 7-maceration from prolonged immersion 8-allergic contact dermatitis (e.g. to nail hardener) 9-hyperthyroidisim Treatment: -all of the separated nails removed -fingers kept dry -avoid exposure to contact irritants -short course of fluconazol may have to be repeated as the nail grows
Onycholysis
2. Photoonycholysis: onycholysis may be precipitated by exposure to ultra violet radiation. Photoonycholysis may occur with use of Tetracycline & cytotoxic drugs Nail changes with taxanes, primarily docetaxel, prolonged weekly paclitaxel & anthracyclines cause onycholysis, which may be precipitated by exposure to sun light, patients receiving these drugs should protect their nails from sun light. The reaction does not warrant discontinuation of therapy 3. Nail & Cuticle biting: is a nervous habit that begins in child hood & lasts for years, one or all nails may be chewed as far as the lunula The nail plate is chiseled & bitten from the nail bed by the teeth. Thin strips of skin of the lateral & proximal nail fold may also be striped *patients aware of their habit but seem powerless to control it. Treatment: -painting the nail with distasteful preparation -habit reversal by competing response 4. Nail plate excoriation: digging or excoriating the nail plate much less common than biting this destructive practice may result in gross deformity of the nail plate 5. Hangnail: triangular strips of skin may separate from the lateral nail folds, particularly during winter more attempts at removal may cause pain & extension of the tear into the dermis. Separated skin should be cut before extension occurs. Constant lubrication or the finger tips with skin creams & avoidance of repeated hand immersion in water is beneficial
6- Ingrown toenail: ingrown fingernail & toenails are common & the large toe is most frequent affected, the nail pierces the lateral nail fold & enters the dermis where it acts as foreign body *the 1st sign is pain & swelling & the area of penetration becomes edematous & purulent as exuberant granulation tissue grows along side the penetrating nail. *ingrown nails are caused by lateral pressure of poorly fitting shoes, improper or excessive trimming of the lateral nail plate or trauma Treatment: -ingrown nail without inflammation: separation of the distal anterior tip & lateral edges of an ingrown toe nail from the adjacent soft tissue with wisp of absorbent cotton -ingrown nail with inflammation: the lateral nail fold is infiltrated with 1% or 2% lidocaine & nail splitting scissors used to cut wedge shaped nail & remove it. 7. Subungual hematoma: caused by -trauma to the nail plate which cause immediate bleeding and pain -the quantity of blood may be sufficient to cause separation & loss of the nail plate -the traditional method of puncturing the nail with red-hot paperclip tip remains the quickest & most effective method of draining the blood, no anesthesia is required with this procedure 8. Nail hypertrophy: gross thickening of the nail plate may occur with tight-fitting shoes or other forms of chronic trauma. -the nail plate is brown, very thick & points to one side
Subungual hematoma
C/the nail & internal disease: a. Beau's lines: are transverse depressions of all of the nails that appear at the base of the lunula weeks after a stressful event has temporarily interrupted nail formation. The lines progress distally with normal nail growth & eventually disappear at the free edge. They develop in response to many diseases such as syphilis, uncontrolled DM, myocarditis, peripheral vascular disease & zinc deficiency & to illnesses accompanied by high fevers such as scarlet fever, measles, mumps, hand-foot-mouth disease & pneumonia & to chemotherapeutic agents b. Yellow nail syndrome: *the spontaneous appearance of yellow nails occurs before during or after certain respiratory diseases & in diseases associated with lymphedema *patients note that nail growth slows & appears to stop *the nail plate may become excessively curved & it turns dark yellow *the nails shows as increased curvature about the long axis, & the cuticle & lunulae are lost & usually all the nails are involved *the disease associated with edema of lower extremities, facial edema, plural effusion, bronchiectasis, sinusitis, bronitis& chronic respiratory infection C. Spoon nails: lateral elevation & central depression of the nail plate cause the nail to be spoon shaped this is called (Koilonychia) cause: -normal children may have it & persist a life time -iron deficiency anemia -idiopathic hemochromatosisBeau lines
Yellow nail syndromeKoilonychia
d. Finger clubbing (Hippocratic nails): is distinct feature associated with a number of diseases, but may occur as a normal variant. The distal phalanges of the fingers & toes are enlarged to a rounded bulbous shape. The nail enlarges & becomes curved, hard & thickened Causes: Lung diseases, cardiovascular diseases, cirrhosis, colitis & thyroid disease * The changes are permanent D/ Congenital anomalies: -numerous congenital syndromes involve nail changes -the most widely understood syndromes all have autosomal dominant inheritance patterns 1. Pachonychia congenital: yellow. Very thick nail beds with elevated nails, palmer & plantar hyperkeratosis & white keratotic thickening of the tongue 2. Nail patella syndrome: defective short nails & small or absent patella E/Color & drug induced changes: change in nail color may result from color change in nail plate or nail bed 1. Brown nails: antimalarial drugs, cytotoxics, junctional nevi hyperbilirubinemia, malnutrion, Addison disease, melanoma, normal finding in black, photographic developer 2. Green nails: pseudomonas 3. Blue nails: Zidouvdine, antimalarial, minocycline, Wilson disease & hemorrhage F/ Tumors: A limited number of tumors have been reported to occur about & under the nails