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Mastocytosis_DermClin1
A solitary, oval and nontender nodule appeared spontaneously on the chest of a boy aged 9 months. The 1.5-cm x 1.0-cm nodule was located on the lateral aspect of the left chest wall and had a yellowish-brown center, a peau d’orange surface appearance and had developed an erythematous surrounding base when palpated. The child’s history included eczema, bilateral ear infections and wheezing with upper respiratory infections. All of the child’s immunizations were up to date. His medications included fluoride supplementation, and he had no known allergies. The child was afebrile and asymptomatic. Submit your answer and read the full explanation below. If you like this activity or have a suggestion, tell us about it in the comment box at the bottom of the page.Do you have related images that you would like to share? Click on the “+Image” link under the comment box to upload your photos. By submitting your photo, you agree that the patient in the photo is not identifiable or has signed a waiver in compliance with HIPAA regulations.
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Mastocytosis is a disorder that is characterized by mast cell proliferation with accumulation within various organs, most often the skin.1 Most children present with transient cutaneous cases. Systemic involvement is possible in children; however, it is rare.2
The major classification subgroups for childhood mastocytosis include cutaneous mastocytosis (CM), indolent systemic mastocytosis, systemic mastocytosis (SM) with an associated clonal hematologic nonmast cell linage disease, aggressive systemic mastocytosis, mast cell leukemia, mast cell sarcoma and extracutaneous mastocytoma.1
CM in children can be classified further into four common forms: urticaria pigmentosa, mastocytoma of the skin, diffuse cutaneous mastocytosis and telangiectasia macularis eruptiva perstans.1 Types of mastocytosis include solitary mastocytoma, paucicellular mastocytosis and urticarial pigmentosa. Of these, urticarial pigmentosa is the most common and presents as oval or round red-brown macules, papules or plaques numbering from a few to thousands.1
Mastocytosis affects infants and children twice as frequently as it does adults.3 Most of the patients diagnosed with mastocytosis are children, with 75% of the cases occurring in infancy or early childhood and peaking again in patients aged 30 to 49 years.1 Mastocytosis affects males and females equally, and most reported cases are in individuals of Caucasian decent.1
A diagnosis for this patient was made from the history, physical examination and a positive Darier’s sign.
When diagnosing a child with suspected mastocytosis, a thorough history and comprehensive physical examination of the skin should be completed. Documentation should include duration of the disease (noting any increases or decreases in lesions), exacerbating factors (e.g., heat, exertion, food, and medications), family history and lesion characteristics (e.g., pruritus, erythema)2
The Darier’s sign, induced by gently stroking, rubbing or scratching a small area of the affected skin, should be performed on any suspicious areas.1-4 A positive sign is the development of erythema over or around the lesion and indicates the presence of mast cells within the lesion. This change is attributable to the mast cell degranulation induced by the physical stimulation.1 To prevent progression to generalized flushing and hives, uncontrolled rubbing or scratching of mastocytomas should be avoided in those with a history of a systemic reaction.1
The Dariers’s sign is highly specific for mastocytosis. In combination with clinical findings, it may be more accurate than a skin biopsy.3 A 3-mm punch biopsy is useful when the diagnosis is unclear. Specimens should be placed in formalin and undergo histopathologic staining with Giemsa.2,4
Further testing may include a complete blood count with differential, liver function tests, plasma or urinary histamine levels, and serum tryptase. Bone marrow biopsies are not usually performed in children but may be done if the findings suggest SM; if there are abnormalities on the blood count; or if hepatomegaly, splenomegaly, or lymphadenopathy are noted.2,4,5
Differential diagnoses include carcinoid, lentigo, herpes simplex, linear immunoglobulin A dermatosis, lymphocytoma cutis, cutaneous pseudolymphoma, epidermis bullosa, macular amyloidosis, nodular localized cutaneous amyloidosis, melanocytic naevi xanthomas, or juvenile xanthogranulomas.
Most children experience complete regression of symptoms by puberty with no systemic involvement. The prognosis depends on the age of onset. Individuals who exhibit signs before age 2 years often have an excellent prognosis, with resolution by puberty. Those with onset after age 10 years tend to have a poorer prognosis; the mastocytosis tends to be more persistent, is often associated with systemic findings, and carries a higher risk of malignant transformation.1
There is no cure for mastocytosis, and treatment is aimed at symptomatic relief and avoidance of triggers. Histamine 1 (H1) and histamine 2 (H2) blockers are useful in decreasing pruritus and flushing. Oral disodium cromoglycate is another option to alleviate pruritus, whealing, and flushing. Additionally, epinephrine auto-injectors (EpiPens) are often prescribed for potential anaphylaxis due to excessive mast cell mediator release.6 Advise patients to avoid medications that may precipitate mediator release. Triggers include but are not limited to medications (e.g., morphine, codeine, aspirin, nonsteroidal anti-inflammatory drugs, polymyxin B, vancomycin [Vancocin], quinine), neuromuscular blocking agents (i.e., succinylcholine [Anectine], tubocurarine, scopolamine [Transderm Scop], pancuronium [Pavulon]), and all types of radiographic contrast media.1,2,5 Measures should be taken to avoid dietary and physical triggers. Foods that induce mast cell mediator release (e.g., hot/spicy foods, alcohol, cheese, shellfish, hot drinks, and food containing metabisulfites) should be avoided.1,2,5 Other triggers include such physical stimuli as emotional stress, temperature extremes, physical exertion, and excessive rubbing of the skin.1
Education should be aimed at the avoidance of physical triggers and other substances that can initiate a reaction. Individuals with mastocytosis should be informed of the importance of notifying all health-care personnel of the diagnosis so that appropriate measures can be taken to avoid triggers and ensure safety.
The child in this case was treated symptomatically with H1 antihistamines, given an EpiPen kit, and followed yearly. The parents were educated regarding the diagnosis and triggers and given instructions about how and when to use the EpiPen. The child’s mastocytoma resolved over weeks, and he had no further lesions or systemic involvement.
Susan Weinhofer, RN, is enrolled in the Family Nurse Practitioner program at Carlow University in Pittsburgh. After completing the program in December, she will work in a pediatric primary-care office in Greensburg, Penn. The author has no relationships to disclose regarding the content of this article.
References
1. Medscape Reference. Mastocytosis.
2. Heide R, Beishuizen A, De Groot H et al. Mastocytosis in children: a protocol for management. Pediatr Dermatol. 2008;25:493-500.
3. Hannaford R, Rogers M. Presentation of cutaneous mastocytosis in 173 children. Australas J Dermatol. 2001;42:15-21.
4. Castells MC et al. UpToDate. Evaluation and diagnosis of mastocytosis (cutaneous and systemic).
5. Castells MC et al. UpToDate. Treatment and prognosis of cutaneous mastocytosis.
6. Brockow K, Jofer C, Behrendt H, Ring J. Anaphylaxis in patients with mastocytosis: a study on history, clinical features and risk factors in 120 patients. Allergy. 2008;63:226-232.
All electronic documents accessed November 7, 2011.
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