Bacteria & Yeast
Bacteria and yeast
can infect the skin structures around the nail and cause a
of acute and chronic infections. Infection
of the lateral or proximal nail folds is called
paronychia. Acute paronychia is usually caused by
Staphylococcus aureus. Chronic paronychia is caused by
many different bacteria and yeasts such as candida.
Pseudomonas is a
bacteria that thrives in a warm moist environment. It
grows if a
space is created between the under surface of
the nail plate and the nail bed. The bacteria makes a
green pigment and stains the nail plate.
The buttons on the
left lead to descriptions of these diseases.
evolves slowly and presents initially with tenderness and
swelling about the proximal and lateral nailfolds. Individuals
whose hands are repeatedly exposed to moisture (e.g., bakers,
dishwashers, and dentists) are at greatest risk. Manipulation of
the cuticle accelerates the process. Typically, many or all
fingers are involved simultaneously. The cuticle separates from
the nail plate, leaving the space between the proximal nailfold
and the nail plate exposed to infection.
organisms, both pathogens and contaminants, thrive in this warm,
moist intertriginous space. The skin about the nail becomes pale
red, tender or painful,
and swollen. Occasionally a small quantity
of pus can be expressed from under the proximal nailfold.
of this material may grow Candida or gram-positive and
gram-negative organisms. The nail plate is not infected and
maintains its integrity, although its surface becomes brown and
rippled. There is no subungual thickening such as that present in
some fungal infections. The process is chronic and responds very
slowly to treatment. Psoriasis of the fingers may present in a
attempt must be made to keep the hands dry. One should avoid using
medicines with an ointment base, because they are too occlusive
and interfere with the necessary drying process. Patients should
refrain from washing dishes and from washing their own hair.
Rubber or plastic gloves are of some value, but moisture
accumulates in them with prolonged use.
antibiotics do not penetrate this distal site in sufficient
concentration. Furthermore, the variety of organisms is too
numerous to respond to a single oral agent. The most effective
treatment is to place one or two drops of 3% thymol in 70%
ethanol, which must be compounded by a pharmacist, at the proximal
nailfold and to wait for this liquid to flow by capillary action
into the space created by the absent cuticle. Slight elevation of
the proximal nailfold with a flat toothpick facilitates
penetration. This should be repeated two or three times a day for
weeks, until the cuticle is re-formed. The cuticle may never
re-form in patients with long-standing inflammation.
(150 mg/day) for 1 to 4 weeks may control chronic inflammation.
Short courses of fluconazole may have to be repeated as the
The rapid onset of painful, bright red swelling of the proximal and
lateral nailfold may occur spontaneously or may follow trauma or
manipulation. Superficial infections present with an accumulation of
purulent material behind the cuticle. Staphylococcus is the most common
organism but contamination by other bacteria and yeast is possible.
The small abscess
is drained by inserting the pointed end of a comedone extractor or similar
instrument between the proximal nailfold and the nail plate. Pain is
abruptly relieved. A diffuse, painful swelling suggests deeper infection,
and cases that do not respond to antistaphylococcal antibiotics may
require deep incision. Acute paronychia rarely evolves into chronic
Repeated exposure to soap and water causes maceration of the hyponychium
and softening of the nail plate. Separation of the nail plate
(onycholysis) exposes a damp, macerated space between the nail plate and
the nail bed, which is a fertile site for the growth of Pseudomonas.
The nail plate
assumes a green-black color. There is little discomfort or inflammation.
This presentation may be confused with subungual hematoma, but the absence
of pain with Pseudomonas infection establishes the diagnosis. Applying a
few drops of a one part chlorine bleach/four parts water mixture under the
nail three times a day controls the infection.
to the nail unit can produce a variety of changes to the nail plate,
nail bed and skin surrounding the nail. These changes may be easily
confused with other nail diseases. Some of the most common changes
can be seen by pushing the buttons on the left
the painless separation of the nail from the nail bed, is common.
Separation usually begins at the distal groove and progresses
irregularly and proximally, causing part or most of the plate to
become separated (Figure 25-20). The nonadherent portion of the nail
is opaque with a white, yellow, or green tinge. The causes of
onycholysis include psoriasis, trauma, Candida or Pseudomonas
infections, internal drugs,24 PUVA photochemotherapy,25 contact with
chemicals, maceration from prolonged immersion, and allergic contact
dermatitis (e.g., to nail hardener).26,27
signs of skin disease are absent, onycholysis is most frequently
seen in women with long fingernails. With normal activity, the
extended nail inadvertently strikes objects and acts as a lever to
pry the nail from the nail bed. Forcing a stylus between the nail
plate and bed while manicuring can cause separation.
Photoonycholysis may occur with the use of tetracycline antibiotics.
All of the
separated nail is removed, and the fingers are kept dry. Removing
the separated nail eliminates the lever, and dryness discourages
infection. One should not cover the cut nails; occlusion promotes
maceration. Any form of manipulation should be discouraged.
Splitting or peeling of the skin around the nail is called a
hangnail. It occurs in predisposed people especially during the
cold, dry winter months. It is often resistant to treatment and
causes chronic pain.
Avoid frequent hand washing
and exposure to activites that involve frequent contact with
water. Heavy moisturizers such as Aquaphore ointment are soothing
and promote healing.
Anatomy of the nail bed
The nail bed
consists of parallel longitudinal ridges with small blood vessels at their
base. Bleeding induced by trauma or vessel disease, such as lupus, occurs
in the depths of these grooves, producing the splinter hemorrhage pattern
viewed through the nail plate and illustrated in the pictures above.
may be caused by trauma to the nail plate, which causes immediate bleeding
and pain. The quantity of blood may be sufficient to cause separation and
loss of the nail plate. The traditional method of puncturing the nail with
a red-hot paperclip tip remains the quickest and most effective method of
draining the blood. Trauma to the proximal nailfold causes hemorrhage that
may not be apparent for days. The nail plate may emerge from the nailfold
with blood stains that remain until the nail grows out.
spots or bands
(leukonychia punctata) in the nail plate, a very common finding,
possibly result from cuticle manipulation or other mild forms of
trauma. The spots or bands may appear at the lunula or may appear
spontaneously in the nail plate and subsequently disappear or grow
with the nail.
deformity is a common finding and is caused by biting or picking a section
of the proximal nailfold of the thumb with the index fingernail. The
resulting defect consists of a longitudinal band of horizontal grooves
that often have a yellow discoloration. The band extends from the proximal
nailfold to the tip of the nail.This should not be confused with the nail
rippling that occurs with chronic paronychia or chronic eczematous
inflammation of the proximal nailfold. The ripples of chronic inflammation
appear as rounded waves,in contrast to the closely spaced, sharp grooves
produced by continual manipulation.
The method of
formation is demonstrated for the patient. Some patients are not aware of
their habit, and others who admit to nail picking may not realize that
they have created the defect. Patients who discontinue manipulation are
able to grow relatively normal nails; there are those, however, who find
it impossible to stop.
Psoriasis of the
occurs simultaneously with skin disease but may occur as an isolated
finding and be confused with several other disease. Psoriasis of the nails
is often misdiagnosed as a fungal infection.
The incidence of
nail involvement in psoriasis varies from 10% to 50%. There are
several characteristic changes that occur. One or all of these changes may
be present . Pitting, onycholysis (nail plate separation, discoloration,
subungual thickening, and nail-plate alterations take place.
Pitting, or sharply
defined ice picklike depressions in the nail plate, is the most common
finding. The number, distribution, pattern, and depth vary. Pitting is
observed in normal nails and with alopecia areata, but, in general,
psoriatic pits are deeper. Pits form as the nail substance is shed, which
is a process analogous to the shedding of psoriatic skin scale.
subungual debris, nail plate distortion
Separation of the
nail from the nail bed, or onycholysis, is common. Onycholysis is
frequently accompanied by yellow discoloration. Separation begins at the
distal groove or under the nail plate and may involve several nails.
as an isolated finding in women with long fingernails. Minor trauma causes
the separation. Yeast often grows in the space between the nail plate and
and plate distortion
Psoriasis of the
hyponychium results in the accumulation of yellow, scaly debris that
elevates the nail plate. The debris is commonly mistaken for nail fungus
infection. Severe psoriasis of the matrix and nail bed results in grossly
malformed nails, and nail-bed splinter hemorrhages are common .
Psoriasis of the nail matrix
results in many different patterns of distortion. Isolated inflammatory
lesions of the proximal matrix cause pits. Diffuse inflammation of the
anterior matrix causes the pattern illustrated here. The entire surface is
rough and distorted. Patients with this isolated finding think that they
just have ruff nail and are unaware of the etiology. A careful search for
subtle signs of psoriasis in other body areas (e.g. scalp scale, gluteal
pinking) is indicated.
Oil spot lesions
Oil spot lesions are caused by
separation of the nail from the nail bed. Serum and cellular debris
accumulate and become trapped in this space. The yellow color is highly
characteristic. This nail also has a few pits on the surface.