Juvenile Xanthogranulomas and Alopecia Areata

Case 1:

This infant's mother noted the development of 2 reddish-pink firm papules on her son's forehead when he was about 1 month old. These are the only lesions present, and they are asymptomatic. The only change in the lesions has been their color, which is now yellow-orange.

Do you need a biopsy to make the diagnosis?

Case 1: These are juvenile xanthogranulomas (JXGs)--common, benign, self-healing non-Langerhans cell histiocytic tumors of the skin. Approximately 70% develop within the first year of life, and 20% are present at birth. Typically, these lesions measure from 2 to 20 mm in diameter and may be classified as micronodular (2 to 5 mm) or macronodular (5 to 20 mm). Lesions are solitary in more than 70% of patients, and most occur on the head, neck, and upper trunk. The onset of the lesion(s) is usually abrupt, but new lesions may develop over years.

JXGs can vary in number (1 to hundreds), in size (up to 10 cm), in location (they may be present at any body site), and in morphology (plaques, hyperkeratosis), which complicates diagnosis. Fortunately, histologic diagnosis is rarely problematic. Typical lesions generally do not require a biopsy for diagnosis, however.

As a consultant, I am frequently asked questions not just about diagnosis but also about the need for ophthalmologic consultation and the possibility of systemic involvement in patients with JXG. Extracutaneous involvement is rare. It is estimated that fewer than 0.5% of patients with cutaneous disease have ocular involvement, in which the manifestations are related to the mass effect of the JXG lesions. There is a clinical impression that patients under 2 years and those with multiple smaller lesions (micronodular variant) are more likely to have eye involvement. I generally refer these patients for assessment. Otherwise, I only suggest investigations looking for systemic involvement based on the presence of signs and symptoms. There are no associated metabolic abnormalities in patients with these lesions.

If a patient with JXG has cutaneous findings of neurofibromatosis 1, be sure to look for associated juvenile chronic myeloid leukemia--which is rare but which has been reported.

JXGs resolve spontaneously, but you may wish to excise them early because the resultant scars may be unsightly with atrophy and/or significant post-inflammatory pigmentation. If lesions are large, ulcerated, or symptomatic (because of their location), I recommend excision without waiting for resolution.

Case 2:

This adolescent presented with a 1-month history of an asymptomatic expanding area of hair loss over the occiput of his scalp. The characteristic and pathognomonic physical sign is present in the pen-marked area.

What are the chances that this teenager will lose all his hair?

Case 2: Alopecia areata (AA) usually presents as one or more localized areas of hair loss--typically on the scalp--that develop as an expanding oval patch or patches without cutaneous signs of inflammation, scarring, or scaling. The condition is common (the estimated incidence is 17 per 100,000). Between 25% and 50% of affected persons have a first episode before their 16th birthday, and approximately 20% of children have a family history of this condition. AA is associated with a number of autoimmune diseases. The chief association is with thyroid disease: 10% of patients with AA have a thyroid disorder.

The clinical presentation is usually so distinct that the diagnosis is easily made. The presence of "exclamation point" hairs should be sought, because these are pathognomonic for AA. Exclamation point hairs are found at the periphery of the alopecic patches and are often misinterpreted by patients as signs of regrowth because they are short and stubbly and suggest new hairs. In fact, these are dystrophic hairs with light-colored bottoms that taper as they approach the scalp and broaden and pigment distally to give the appearance of the punctuation mark. Unfortunately, these hairs represent active disease. A pull-test is often positive: hairs easily removed from the periphery of the patches signify very active disease.

The hopeful sign is regrowth, which usually occurs with fine, de-pigmented hairs that, over time, repigment and acquire the characteristics of their original state. It is not unusual to observe the progression of loss in one patch at the same time that regrowth is occurring in an adjacent patch.

AA is a fickle condition. There is no way to predict its ultimate behavior, although onset at an early age, the presence of atopy or other immune diseases, multiple patches, a family history, and a hair loss pattern described as oophiasis (a band-like loss around the edge of the scalp at the occiput and ears) have all been associated with a poor prognosis for spontaneous regrowth.

Treatment is equally frustrating, because current methods aim to stimulate regrowth within individual patches and do not affect the natural course of the condition. Fortunately, if only a few areas are present, spontaneous regrowth will occur within a year in 95% of affected children. Fewer than 10% will suffer a recurrence.

The most important component of the initial consultation is to educate the patient and (when appropriate) the parents about the natural history and prognosis of the condition and to provide educational support. The best Internet resource I have found is the National Alopecia Areata Foundation (www.naaf.org); I recommend that their reading begin here. As you can imagine, this condition is ripe for exploitation by medical charlatans. Legitimate patient support groups are our best defense. I also recommend the book Alopecia Areata: Understanding and Coping With Hair Loss, which not only discusses the condition but also sets out the available treatment options in lay language and in good detail.¹

If I am considering treatment, I use the algorithm published by Drs Madani and Shapirothat separates modalities based on the patient's age and the extent of disease.² Children of any age with less than 50% of their scalp involved are given the choice of avoiding therapy and awaiting spontaneous resolution. If a child requests therapy and is old enough (generally over 10 years) to tolerate intralesional injections of corticosteroids, I will inject 5 µg/mL of triamcinolone about the periphery of the patches. If the child will not tolerate injections, I offer a 3-month trial of a 5% minoxidil solution applied twice daily with the concomitant application of a potent topical corticosteroid or short-contact anthralin therapy. If a child over age 10 has lost more than 50% of his or her scalp hair, I routinely offer topical diphenylcyclopropenone (DPCP) immunotherapy.

References:

REFERENCES:

1. Thompson WJA, Shapiro J, eds.

Alopecia Areata: Understanding and Coping With Hair Loss.

Baltimore: The John Hopkins University Press; 1996.
2. Madani S, Shapiro L. Alopecia areata update.

JAMA.

2000;42:549-566.