CONTRIBUTOR
BENJAMIN BARANKIN, MD, FRCPC, dermatologist in private practice, Toronto, Ontario, Canada; and member, Patient Care Subspecialty Advisory Board.
This article offers suggestions for easier recognition and management of some of the most common dermatologic conditions seen
in primary care. For those of us who treat both adults and children, it is also important to keep in mind that the management
of skin lesions in youngsters differs from the approach used in adults. Physicians should avoid unnecessarily traumatizing
or scarring children; invasive diagnostic techniques such as skin biopsies should be reserved for when they are essential
to the management of the disease. Proper education of the parent and child, the use of distraction to allay fear, and an appreciation
of the maturity of the child when deciding on treatment are all beneficial strategies in the management of skin problems in
the pediatric population.
Actinic keratosis
Actinic keratosis
|
The lesions of actinic keratosis are small (<1 cm), single or multiple, discrete, sandpaper-rough, and scaly. They occur on
chronically sun-exposed and sun-damaged skin, usually in the elderly, and are found primarily on the head and neck, as well
as the dorsum of the hands and forearms. Approximately 1 in 1000 of these precancerous lesions develop into squamous cell
carcinoma if left untreated. Treatment
Liquid nitrogen cryotherapy is the most common treatment. Multiple lesions can be treated with topical 5-fluorouracil, imiquimod
(Aldara), chemical peels (eg, glycolic acid or trichloroacetic acid [Tri-Chlor]), and photodynamic therapy.
Dermatofibroma
Dermatofibroma
|
The lesion of dermatofibroma is a small (<1 cm), firm, raised nodule, which is slow-growing and usually painless. This skin-colored/pink/red/brown
nodule is typically solitary, more common in women and the middle-aged, and usually found on the extremities (especially the
legs). The lesion is sometimes associated with a recent history of trauma, such as an insect bite or a ruptured cyst. Clinical
diagnosis can be supported by the presence of a dimple sign: lateral compression with the finger and thumb produces a depression
or dimple in the lesion.
Treatment
Because of the benign and asymptomatic nature of this condition, treatment is unnecessary, but liquid nitrogen cryotherapy
can be effective in flattening the lesion. Surgical excision is also an option.
Impetigo
Impetigo
|
This infectious skin disease, spread by direct contact, is most common in children. It is usually associated with an underlying
eczema or atopic dermatitis that has been excoriated and secondarily infected. Impetigo can be primary or secondary, and there
are 3 types: nonbullous impetigo, bullous impetigo, and ecthyma. More than 90% of cases are due to Staphylococcus aureus; occasionally, impetigo may be the result of group A beta-hemolytic streptococcus (GABHS) or a combination of S aureus and GABHS. It presents as a weeping area of 1- to 3-cm rounded lesions that heal with honey-colored crusts. Lesions typically
last from days to weeks and resolve promptly with treatment. Treatment
Preventive care (checking family members for impetigo) may be required, as well as topical treatment (eg, mupirocin [Bactroban,
Centany]) or systemic treatment (depending on the organism, although cephalexin [Keflex, Panixine DisperDose], or erythromycin
is a good option for 10 days). Consider intranasal topical therapy for recurrent impetigo and reduction of S aureus carriage.
Intertrigo
A malodorous dermatitis of flexural regions that is often secondary to bacterial or yeast infections, intertrigo most commonly
affects the axillae and the inframammary, groin, and intergluteal areas. It initially appears as pustules on an erythematous
base that become confluent, and it needs to be differentiated from erythrasma and inverse psoriasis.
Treatment
Management involves keeping the area clean, cool, dry, and separated. Treatment options include nystatin cream twice daily,
as well as topical mild corticosteroids and powders, which can be compounded together. Zinc oxide paste can also be beneficial.
Head lice
This infestation of the scalp by wingless insects spread by direct contact (shared items or head-to-head) occurs mainly in
children. Infestation is not related to poor hygiene. Head lice are difficult to see, especially because most patients have
fewer than 10 lice; diagnosis is by clinical findings confirmed by finding nits or lice. Although the condition is usually
asymptomatic, itching is intolerable in some cases and can result in secondary infection (ie, occipital or cervical lymphadenopathy
may be suggestive of lice). The eggs/nits are 1 mm, oval, grey-white, and firmly attached to the base of the hair shaft. These
parameters form the clinical basis for diagnosis and differentiation from dandruff, in which the scales are easily removed.
Treatment
Permethrin (Acticin, Elimite, Nix) 1% is the preferred treatment, and reduces reinfestations because of a protective residual.
Treatment should be repeated in 7 days, however. Other treatments are pyrethrin (Lice-Aid, Lice Treatment Max Strength), malathion
(Ovide), oral ivermectin (Stromectol), petrolatum, and, less common now, head shaving. Note that resistance to all topical agents has been reported.
Prevention
Contact with possibly contaminated items (eg, hats and combs) should be avoided. Bedding, clothing, and headgear should be
washed and heat dried, and the environment should be vacuumed, given that lice can survive up to 55 hours off the head. Contacts
should also be treated.
Molluscum contagiosum
Molluscum contagiosum
|
This self-limiting (lasting 6-9 mo) viral infection of the skin is caused by the pox virus. It most commonly affects children
and sexually active adults. The lesions are 1- to 5-mm smooth, firm, white/pink umbilicated papules found anywhere on the
skin. They may be single or multiple (especially if the patient is immunocompromised; multiple facial mollusca may suggest
HIV infection). Although itching, tenderness, or pain is uncommon, an eczematous dermatitis develops around the lesion in
about 10% of patients.
Treatment
Curettage, liquid nitrogen cryotherapy, electrodesiccation, topical cantharidin, or imiquimod may be used. In children, topical
cantharidin or imiquimod is preferred. Oral cimetidine has been reported by some to be effective in children with widespread
or facial molluscum.
Scabies
This parasitic infection is usually transmitted by direct contact. Older patients in nursing homes are more prone to infestation,
as are young children and sexually active young adults. Patients present with an itchy, eczematous, papular rash that occurs
most commonly in the finger webs and the flexor aspect of wrists, elbows, buttocks, and genitalia, with sparing of the head
and neck. With the initial infection, sensitization and pruritus take a few weeks to develop. After a reinfestation, however,
pruritus develops within 24 hours. Because it can be difficult to make a clinical diagnosis, a scabies infection should be
in the differential diagnosis in the setting of persistent generalized pruritus, which is often intense, widespread, and worse
at night, as it interferes with sleep. Unfortunately for some patients, this condition has been misdiagnosed and chronically
mistreated as eczema.
Treatment
Permethrin 5% cream is the most reliable topical scabicide with no toxicity or residual effects. Other treatments include
malathion, oral ivermectin, and antihistamines (to reduce pruritus and improve sleep). Treatment is effective in more than
90% of cases. Clothes and bedding must be laundered in hot water. Close personal and household contacts must be treated at
the same time, often regardless of symptoms. Be aware that pruritus may persist for weeks after successful treatment.
Skin tags
Skin tags
|
These common lesions are soft, skin- or tan-colored pedunculated polyps that often occur in intertriginous areas and increase
in size and number over time. They are more common in older people, women (especially during pregnancy), and obese patients.
Usually asymptomatic, they may become bothersome and tender after trauma or torsion. Skin tags are completely benign, requiring
management only in case of symptoms or for cosmetic purposes. Treatment
These lesions can be snipped with scissors or treated with liquid nitrogen or electrodesiccation. An anesthetic should be
used before treatment of larger, more pedunculated lesions.
Tinea pedis
A dermatophytic infection of the feet, tinea pedis manifests itself as erythema with scaling and maceration. Usually asymptomatic,
this condition may be itchy, as well as painful if infected. It is often a chronic condition made worse by a hot climate.
The 2 main varieties are interdigital (athlete's foot), which can be a source of cellulitis of the foot, and hyperkeratotic
(moccasin foot).
Treatment
Topical treatment involves miconazole or clotrimazole applied twice daily, ketoconazole (Nizoral, Xolegel) once daily, or
terbinafine (Desenex, Lamisil) once daily for 2 to 4 weeks. If tinea is extensive or topical therapy fails, consider systemic
treatment with itraconazole (Sporanox) or terbinafine.
Prevention
Patients should wear shower shoes in public facilities and wash their feet regularly.
Tinea versicolor
Tinea versicolor
|
This condition appears as a chronic, asymptomatic scaly rash of different colors (white, orange-brown, or dark brown) with
round macules, usually smaller than 1 cm, which liberates scale when scratched. Caused by infection with the yeast Malassezia furfur, it is more common in young adults and appears most often on the upper trunk. Clinical suspicion and a positive potassium
hydroxide preparation test clinch the diagnosis. Treatment
The options include selenium sulfide 2.5% lotion or shampoo applied to the affected area daily for 15 minutes for 1 week.
Topical imidazoles (eg, ketoconazole), terbinafine, and ciclopirox (Loprox, Penlac) are also useful. If widespread, this condition
can be treated with oral ketoconazole or itraconazole.
Warts (common)
Common wart
|
Warts are due to a human papillomavirus infection of the epidermis that is transmitted directly through broken skin. Warts
are found on the fingers, palm, and dorsum of the hand, appearing as firm, rough skin or brown-colored papules with tiny black
dots on the surface. Treatment is only necessary if the warts are bothersome or for cosmetic purposes. Most warts disappear
spontaneously after an average of 2 years. Treatment
The mainstay of treatment is cryotherapy, which often needs to be repeated on several occasions. Daily treatment with OTC
wart-removal preparations (ie, salicylic acid) is helpful but produces a slower response.
Warts (plantar)
These warts (verrucae plantares) appear as discrete round papules with a rough surface, surrounded by a layer of hyperkeratosis.
Although posing less of a cosmetic problem than common warts, plantar warts are more likely to be treated because the hyperkeratosis
may cause pain during walking.
Treatment
The hyperkeratosis should be pared down with a scalpel or pumice stone, which may relieve the pain. Topical OTC salicylic
acid preparations should be recommended for use nightly. If these are ineffective, several courses of liquid nitrogen are
typically used. Managing patient expectations is essential. Patients should initially be told that various treatments may
be tried over many months before the warts resolve. Other treatment options for warts include topical imiquimod or topical
5-fluorouracil (both after paring and under occlusion), cantharidin, surgical excision, and laser ablation.
Drugs mentioned in this article
Cantharidin
Cephalexin (Keflex, Panixine DisperDose)
Ciclopirox (Loprox, Penlac)
Cimetidine
Clotrimazole
Erythromycin
5-Fluorouracil
Glycolic acid
Imiquimod (Aldara)
Itraconazole (Sporanox)
Ivermectin (Stromectol)
Ketoconazole (Nizoral, Xolegel)
Malathion (Ovide)
Miconazole
Mupirocin (Bactroban, Centany)
Nystatin
Permethrin (Acticin, Elimite, Nix)
Petrolatum
Pyrethrin (Lice-Aid, Lice Treatment Max Strength)
Salicylic acid
Selenium sulfide
Terbinafine (Desenex, Lamisil)
Trichloroacetic acid
(Tri-Chlor)
Zinc oxide
SUGGESTED READING
Cole C, Gazewood J. Diagnosis and treatment of impetigo. Am Fam Physician. 2007;75(6):859-864.
de Berker D, McGregor JM, Hughes BR, et al. Guidelines for the management of actinic keratoses. Br J Dermatol. 2007;156(2):222-230.
Gibbs S, Harvey I. Topical treatments for cutaneous warts. Cochrane Database Syst Rev. Jul 19, 2006;3:CD001781.
Gupta AK, Chow M, Daniel CR, et al. Treatments of tinea pedis. Dermatol Clin. 2003;21(3):431-462.
Gupta AK, Ryder JE, Nicol K, et al. Superficial fungal infections: an update on pityriasis versicolor, seborrheic dermatitis,
tinea capitis, and onychomycosis. Clin Dermatol. 2003;21(5):417-425.
Heukelbach J, Feldmeier H. Scabies. Lancet. 2006;367(9524):1767-1774.
Janniger CK, Schwartz RA, Szepietowski JC, et al. Intertrigo and common secondary skin infections. Am Fam Physician. 2005;72(5):833-838.
Lebwohl M, Clark L, Levitt J. Therapy for head lice based on life cycle, resistance, and safety considerations. Pediatrics. 2007;119(5):965-974.
Pierson JC, Pierson DM. Emedicine: dermatofibroma. http://www.emedicine.com/DERM/topic96.htm. Accessed August 3, 2007.
Schwartz RA, Terlikowska A, Patterson WM. Emedicine: achrochordon. Available at http://www.emedicine.com/derm/topic606.htm. Accessed August 3, 2007.
Turchin I, Barankin B. Dermacase. Molluscum contagiosum. Can Fam Physician. 2006;52(11):1395,1407.
