Andrew S. Wong, BSc

This 16-year-old boy had slowly progressive hypopigmented lesions on the lower extremities for the past 4 years. He also had atopic dermatitis, asthma, and allergic rhinitis. His 38-year-old mother had Hashimoto thyroiditis. None of his immediate family members had a similar skin disorder.

Well-demarcated, depigmented patches on extensor aspects of lower legs. Remaining findings unremarkable.

Vitiligo is a common acquired pigmentation disorder characterized by depigmented macules/patches as a result of loss of functional cutaneous melanocytes.

 Because of its unsightly appearance, the condition can have considerable impact both psychologically and socially.

PREVALENCE   Vitiligo is estimated to affect 0.5% to 1% of the population   worldwide.

 Its onset occurs before age 10 years   in about 25% of affected persons, before age 20 years in   50%, and before age 40 years in 95%.

 No differences in rates of occurrence according   to race or skin type are apparent, although the condition   is more noticeable in dark-skinned persons.

 Vitiligo is more common in   atopic patients and in patients with a personal or family   history of autoimmune disease.

ETIOPATHOGENESIS   The cause of vitiligo is multifactorial and polygenic.   Genetic, immunological, and neurogenic factors may   play a role.

 It is estimated that 12% to 35% of   affected children and adolescents have a family history   of vitiligo.

 Inheritance may involve genes associated   with regulation of autoimmunity, melanin biosynthesis,   response to oxidative stress, and cell adhesion.

 For instance,   the gene NALP1, encoding NACHT leucine-rich   repeat protein 1, predisposes persons to vitiligo and various   autoimmune diseases.

 Vitiligo is often associated   with Hashimoto thyroiditis and Graves disease.

 The   involvement of autoimmunity in the pathogenesis of   vitiligo (especially in nonsegmental vitiligo) is supported   by the demonstration of circulating autoantibodies to   melanocytes in affected patients.

Accumulation of free radicals toxic to melanocytes   may lead to their destruction.

 Alternatively, melanocytes   might exhibit increased sensitivity to oxidative stress.

   Trauma and friction (Koebner phenomenon) may also   be involved in the pathogenesis of the disease.

In segmental vitiligo, a neurogenic sympathetic disturbance   might be responsible.

 Certain chemical mediators   released from nerve endings might cause decreased   melanin production or destruction of melanocytes.

 In   this regard, elevated neuropeptide Y levels have been   demonstrated in skin of affected persons.

HISTOPATHOLOGY   Histologically, melanocytes are absent in established   lesions.

 A superficial dermal lymphocytic/mononuclear   infiltrate may be seen in the advancing margin of vitiligo,   especially in early lesions.

CLINICAL MANIFESTATIONS   The amelanotic macules/patches of vitiligo typically   appear chalk- or milk-white.

 Lesions often show homogeneous   depigmentation and are well demarcated.

 Pinpoint   depigmentation may precede patchy depigmentation   in rapidly progressing disease.

 A hyperpigmented   rim at the interface of depigmented and normally pigmented   skin may be seen after sun exposure.

 Lesions   are often symmetrical and enlarge centrifugally in size   with time.

 The most common locations are the face, followed   by the neck, lower limbs, trunk, and upper limbs.

 Rarely, the hair, buccal   mucosa, and gingiva may also be affected.

Vitiligo is classified into subtypes on the basis of   the pattern and extent of involvement:
 • Generalized vitiligo, also known as vitiligo vulgaris,   is the most common type and accounts for 33% to 78%   of cases.


 Lesions are widely distributed and usually   symmetrical,

 as was the case in this patient.
 • Universal vitiligo involves more than 80% of the body   surface area and is very rare.


 • Focal vitiligo presents as a solitary macule or a few   macules in a localized area and in no particular pattern.


 • Segmental vitiligo represents unilateral macules in a   dermatomal pattern.

 This type is less likely to be associated   with autoimmune diseases.


 Segmental vitiligo is   more common in children (accounting for 4% to 19% of   cases) than in adults.


 • Acrofacial vitiligo affects periorificial areas and digits.


 • Mucosal vitiligo involves mucous membranes.


 • Trichrome vitiligo has different degrees of   depigmentation.

DIAGNOSIS   The diagnosis is mainly clinical, based on the characteristic   appearance of the depigmented macules/patches   and their propensity to enlarge.

 Wood lamp accentuates   the lesion and may be of benefit in the diagnosis, especially   in persons with skin type I and type II.

 A skin biopsy   is usually not necessary except when the diagnosis is in   doubt. A dopa stain for tyrosinase or a Fontana-Masson   stain for melanin can be used to confirm the diagnosis.

LABORATORY STUDIES   Because of the association with autoimmune diseases,   annual screening with a complete blood cell   count, thyroid-stimulating hormone, antithyroglobulin   antibody, antithyroid peroxidase antibody, fasting blood   glucose, and antinuclear antibody is often recommended   for children with active vitiligo.

DIFFERENTIAL DIAGNOSIS   The differential diagnosis includes pityriasis alba,   tinea versicolor, hypomelanosis of Ito, nevus depigmentosus,   tuberous sclerosis, nevus anemicus, achromic   nevus, oculocutaneous albinism, idiopathic guttate hypomelanosis,   lichen sclerosis, piebaldism, and hypopigmentation   (postinflammatory, chemical-induced, or drug-induced).

 The distinctive features of each condition   allow a straightforward differentiation from vitiligo.

COMPLICATIONS   Affected skin is at risk for sunburn. In addition, vitiligo   can be cosmetically and psychologically devastating,   resulting in lower self-esteem, poor body image, social   anxiety, peer rejection, depression, and stigmatization.

 The psychological impact is greater in dark-skinned persons,   female patients, and in those with lesions in visible   areas.

Vitiligo is also associated with primary open angle   glaucoma.

 The exact mechanism is unknown; however,   glaucoma is about 3.5 times more likely to develop in patients   with long-standing vitiligo (13 or more years).

PROGNOSIS   The clinical course is generally unpredictable.

 Most   patients experience slow progression of the disease   through the appearance of new lesions or enlargement of   existing lesions.

 There may be periods of relative inactivity,   which may last months to years.

 In segmental vitiligo,   lesions tend to progress rapidly at onset and show a   more stable course thereafter.

 Spontaneous repigmentation   of vitiligo is uncommon and is usually incomplete.

MANAGEMENT   In children with skin type I and type II, no active   treatment other than the use of camouflage cosmetics   and sunscreens is usually necessary.

 Tattooing pigment   can be used to cover lesions on the lips.

 Psychological   support should be offered when necessary.

For patients who prefer treatment for cosmetic reasons,   a variety of options are available. The therapeutic   effect of all the treatments varies greatly from one patient   to another, and treatment must be individualized.   Topical corticosteroids and calcineurin inhibitors   (tacrolimus and pimecrolimus) are the treatment of   choice for those with localized disease.

 Potent or very   potent topical corticosteroids may arrest the attack on   melanocytes by the immune system and can repigment   vitiligo.

 Topical tacrolimus and pimecrolimus block   the action of calcineurin, thereby downgrading the transcription   of genes encoding proinflammatory cytokines.

   Topical calcineurin inhibitors are effective in repigmentation   of vitiligo; have a better safety profile; and are generally   preferred for lesions on the face, neck, genitalia, and   intertriginous areas.

 Consider narrowband UVB phototherapy   for those who have widespread or localized   vitiligo associated with a significant impact on quality of   life and in those who do not respond to treatment with   topical corticosteroids and calcineurin inhibitors.

 Surgical   techniques, such as minigrafting, are not recommended   for children.

In several studies, etanercept and infliximab, used for   other indications, were found to reduce or halt progression   of vitiligo lesions refractory to other treatments.

 New York: Nova Science Publishers, Inc. In press.


 Lotti T, Gori A, Zanieri F, et al. Vitiligo: new and emerging treatments.

 Whitton ME, Pinart M, Batchelor J, et al. Intervention for vitiligo. 

 Matin R. Vitiligo in adults and children. 

 TaÃ¯eb A, Picardo M. Clinical practice. Vitiligo. 

 Mazereeuw-Hautier J, Harper J. Vitiligo. In: Harper J, Oranje A, Prose N,eds. 

 Oxford, UK: Blackwell Publishing;2006:1041-1056.


 Halder RM, Chappell JL. Vitiligo update. 

 Huggins RH, Schwartz RA, Janniger CK. Childhood vitiligo. 

 Silva de Castro CC, do Nascimento LM, Walker G, et al. Genetic variants ofthe DDR1 gene are associated with vitiligo in two independent Brazilian populationsamples. 

 Isenstein AL, Morrell DS, Burkhart CN. Vitiligo: treatment approach inchildren. 

 Gawkrodger DJ, Ormerod AD, Shaw L, et al; British Association of Dermatologists,Royal College of Physicians of London, Cochrane Skin Group, VitiligoSociety. Guideline for the diagnosis and management of vitiligo. 

Articles

This 16-year-old boy had slowly progressive hypopigmented lesions onthe lower extremities for the past 4 years. He also had atopic dermatitis,asthma, and allergic rhinitis.

Teen With Progressive Depigmented Patches

A healthy 4-year-old girl passed     a threadlike object in her stool at a     day-care center. She had no diarrhea,     vomiting, or abdominal pain. Stool     had no blood or melena. Child’s     appetite normal.

 Patient born in Canada of a     middle-class family. No history of     traveling.




 Active, alert, well-nourished     patient. Height, 101 cm (50th     percentile); weight, 15.2 kg (25th     percentile). Physical findings normal.     In particular, no excoriation     noted in the perianal area. No signs     of anemia.

, which     enters the host by ingestion of eggs found in fecally contaminated     material.

 In most patients, the roundworm     infection is asymptomatic. In symptomatic patients, clinical     manifestations can vary widely.


Figure – This photomicrograph shows a fertile Ascaris lumbricoides egg (magnification x128).


     Ascariasis is the most common helminthic infection     in humans.

 About 1 billion people have ascariasis     worldwide, of which 4 million cases are in the United     States.

 Ascariasis has high endemicity in tropical and     subtropical areas.

 Predisposing factors include poor     socioeconomic conditions, use of human feces as fertilizer,     and geophagia. Prevalence is greatest in children     aged 2 to 10 years and decreases after 15 years of age.

     The incidence and intensity of infection is the same in   males and females.

 become     infective after 10 to 15 days at 30°C or about 50 days at     17°C in moist soil, where they can remain viable for     up to 2 years.

 When a mature egg (Figure) comes into     contact with bile acids, the larva exits the egg case and     burrows through the intestinal mucosa. The larva     migrates to the liver via the hepatic portal circulation;     then passes through the lungs, trachea, and epiglottis;     and finally reenters the GI tract where it matures.

    New eggs (up to 20,000 a day per adult female worm)     are released into the feces to complete the cycle. This   process takes 9 to 11 weeks from egg ingestion.

-the largest intestinal nematode     parasite in humans-can grow to 35 cm in length and     0.5 cm in thickness.

 An adult worm has a life span of 10   to 24 months.


     Symptomatic patients tend to have higher worm     loads and may present with vague abdominal or respiratory     tract symptoms. The worms may be passed in feces   or escape through the anus.


     In the larval stage, the main clinical complication is     pulmonary ascariasis. An acute transient pneumonitis     (Lffler syndrome) associated with fever, coughing,     wheezing, dyspnea, hemoptysis, pulmonary infiltrates,   and marked eosinophilia may occur.

When the worms reach the     adult phase, a greater variety of clinical     complications may result. Intestinal     ascariasis can cause nausea,     vomiting, epigastric pain, abdominal     discomfort, and diarrhea.

 Intestinal     obstruction may result from worm     bolus, small-bowel volvulus, or     intussusception.

 Intestinal obstruction     is more frequent in children     because of their smaller intestinal     lumens.

 Other intestinal complications     include bowel perforation,     peritonitis, and appendicitis. A     chronic granulomatous peritonitis     can also occur if an adult worm dies   in the peritoneum.

Migration of adult worms into the biliary tree can lead to biliary colic, pyogenic cholangitis, cholecystitis, empyema of the gallbladder, hepatic abscess, septicemia, cholelithiasis, stricture formation, and pancreatitis.

 Rarely, ascariasis can lead to aseptic encephalopathy.

 infection can lead to nutritional     deficiencies. Children with chronic ascariasis typically     have lower levels of serum hemoglobin, ferritin,     retinol, and albumin.

 Chronic ascariasis is associated     with impaired physical growth and intellectual development,   particularly in growing children.


 Other soil-transmitted helminths that may be excreted are the whipworm 

(Trichuris trichiura) and hookworms (Necator americanus and Ancylostoma duodenale)

 infection is best established by microscopic examination of fecal smears for characteristic ova; larvae may also be detected in the sputum.

 If a worm is excreted, pathological examination yields a definitive diagnosis-as was the case in this patient.

Imaging is usually reserved for more severe cases. A chest radiograph or CT scan will display ground-glass opacity in 

 The roundworms usually are not visible on plain abdominal radiographs unless barium contrast is used.

 CT and ultrasonography can help in detecting the worms in both the intestines and biliary system.

 Endoscopic retrograde cholangiopancreatography is useful in visualizing the exact location of roundworms in the biliary system and is usually done in cases in which endoscopic removal of the worm is indicated.

 Magnetic resonance cholangiopancreatography is a less invasive alternative for pinpointing the worm location.


 Benzimidazoles, such as mebendazole (100 mg PO bid for 3 days or 500 mg PO once) and albendazole (400 mg PO once), are effective treatments of intestinal ascariasis in patients of all ages.

 Pyrantel pamoate (11 mg/kg PO once, maximum 1 g) is a suitable alternative.

Surgery may be required for intestinal obstruction. Endoscopic or laparoscopic removal of the worms may be indicated in patients with severe intestinal and biliary system complications.

In regions where the prevalence of ascariasis is greater than 50%, prophylactic treatment with deworming agents for school-aged children can help control the spread of the disease.

 Improved sanitary conditions, proper disposal of human excreta, and discontinuing the use of human fecal matter as a fertilizer are effective long-term preventive measures.

 Ugbomoiko US, Dalumo V, Ofoezie IE, Obiezue RN. Socio-environmental factors    and ascariasis infection among school-aged children in Ilobu, Osun State,    Nigeria. 

 Shah OJ, Zargar SA, Robbani I. Biliary ascariasis: a review. 

 Bethony J, Brooker S, Albonico M, et al. Soil-transmitted helminth infections:  ascariasis, trichuriasis, and hookworm. 

 Nchito M, Geissler PW, Mubila L, et al. The effect of iron and multi-micronutrient  supplementation on Ascaris lumbricoides reinfection among Zambian  schoolchildren. 

 Dent AE, Kazura JW. Ascariasis (Ascaris lumbricoides). In: Kliegman RM,  Behrman RE, Jenson HB, Stanton BF, eds. 

. 18th ed.  Philadelphia: Saunders Elsevier, 2007:1495-1496.
  

 Gangopadhyay AN, Upadhyaya VD, Gupta DK, et al. Conservative treatment  for round worm intestinal obstruction. 

 Park MS, Kim KW, Ha HK, Lee DH. Intestinal parasitic infection. 

 Das CJ, Kumar J, Debnath J, Chaudhry A. Imaging of ascariasis. 

 Jat KR, Marwaha RK, Panigrahi I, Gupta K. Ascariasis-associated worm  encephalopathy in a young child. 

 Wani SA, Ahmad F, Zargar SA, et al. Soil-transmitted helminths in relation  to hemoglobin status among school children of the Kashmir Valley. 

 Al-Mekhlafi MH, Azlin M, Aini UN, et al. Prevalence and predictors of  low serum retinol and hypoalbuminaemia among children in rural Peninsular  Malaysia.

 Jardim-Botelho A, Raff S, Rodrigues Rde A, et al. Hookworm, Ascaris  lumbricoides infection and polyparasitism associated with poor cognitive performance  in Brazilian schoolchildren. 

 Holland CV. Predisposition to ascariasis: patterns, mechanisms and implications.    

 Kurosawa CM, Ito T, Takaki J, et al. The half-life of Ascaris lumbricoides  prevalence in Japanese schoolchildren. 

A healthy 4-year-old girl passed a threadlike object in her stool at a day-care center. She had no diarrhea, vomiting, or abdominal pain. Stool had no blood or melena. Child’s appetite normal.

Author | Andrew S. Wong, BSc

Articles

Teen With Progressive Depigmented Patches

Asymptomatic Girl Who Passes Threadlike Object in Stool