A 3-year-old male came back to clinic for an increasing number of skin lesions. He had been diagnosed by another of the practice’s partners with urticaria pigmentosa 9 months previously. Over the past 2-3 weeks his mother had noted more lesions, although some of them blistered and went away, and the antihistamines that he was taking were less effective. He was waking more at night because of pruritis and was fussier during the day. The past medical and family histories was non-contributory. The review of systems showed no specific fever, flushing, diarrhea, emesis, pain, respiratory problems or syncope.
The pertinent physical exam showed a healthy appearing male who was itching his right arm. His vital signs were normal and his growth parameters were 75-90%. His skin examination showed scattered, non-clustered, 3-7 mm, non-papular brown macules under his chin, at the hair line, trunk, extremities and also one on the right foot sole. Mother noted that the new lesions were under the chin, hair line and on the foot. These seemed to bother him the most per mother’s report. The patient had a wheal and flare reaction when one lesion was stroked. Dermatographism was not seen. The diagnosis of urticaria pigmentosa was made. The patient hadn’t been taking his non-sedating antihistamine daily and this was reinstituted, along with a sedating antihistamine. A consultation to the dermatologist for more aggressive management was made. An Epi-pen® (epinephrine) was also given with proper instructions as a precaution because the patient’s symptoms seemed to be increasing and it was unclear if this could represent a presentation of systemic mastocytosis versus only non-compliance.
Figure 81 – Clinical image of the rash of urticaria pigmentosa on the trunk. Other images can also be viewed in the To Learn More section below.
Urticaria pigmentosa (UP) is one of the cutaneous forms of mastocytosis. Patients can present at birth and 80% of pediatric patients present by age 1, with both genders equally affected. Classical UP lesions in children are more hyperpigmented but may be erythematous, are 5 mm mean diameter and well demarcated. The distribution includes the trunk especially but face, scalp and other areas can be affected. Lesions may be flat or papular and may blister. The blisters resolve without scarring and these episodes usually remit by age 3. Darier’s sign (stroking of a lesion creating a wheal and flare response) is usually positive in patients not taking antihistamines. Dermatographism is usually not seen. Other forms of UP include plaque-like lesions, and nodular lesions, while others are erythematous and telangiectatic. Fortunately most children and adults do well with the disease and most children remit by adolescence.
UP may be the first presentation of systemic mastocytosis so a history of other problems is important. Because mast cells release granules and other mediators such as histamine, leukotrienes, prostaglandins, platelet-activating factor and interleukins, other symptoms may occur and include:
- Allergic – anaphylaxis
- Cardiovascular – flushing, palpitations, syncope
- General – fatigue, fever, weight loss, night sweats, pain
- Gastrointestinal – abdominal pain, diarrhea, nausea and emesis
- Pulmonary – wheezing
- Neurology/Psychiatry – depression, inattention, irritability, poor memory, personality changes
For patients with mainly pruritis and wheals, which is most patients with UP, daily treatment with non-sedating H1 antihistamines usually works. Other options include adding a sedating H1 antihistamine, a H2 antihistamine (such as cimetidine) or a tricyclic antihistamine such as doxepin.
For any patient at risk for anaphylactic reactions, an emergency kit including epinephrine should be available at all times.
Treatment for mastocytosis includes:
- Avoidance of these triggers
- Irritation of the skin
- Insect stings – especially hymenoptera stings may have a more pronounced effect
- Temperature extremes including sudden changes in temperature
- Medication – non-steroidal anti-inflammatory medication, codeine, morphine, meperidine, general anesthesia, iodonated contrast media, and other drugs
- Increased awareness that these may increase the mast cell response
- Food intake (but not specific foods)
- Physical exercise
- Specific triggers for the individual patient
- Antihistamines – prevent release of histamine
- H1 antihistamine
- H2 antihistamines
- Cromolyn sodium – stabilize the mast cells
- Sunlight exposure
- Surgical excision of the lesions
- Antihistamines – prevent release of histamine
- Specific treatment for certain clinical presentations
- Calcium and Vitamin D
- Hormone treatment
- Leukotriene antagonist
- Non-steroidal antiinflammatory drugs
- Bone marrow transplant
Questions for Further Discussion
1. What else is in the differential diagnosis of urticaria pigmentosa?
2. What counseling instructions do you give families regarding emergency epinephrine use?
- Disease: Urticaria Pigmentosa | Itching | Skin Pigmentation Disorders
- Symptom/Presentation: Non blistering, Nonerythemous Lesions | Urticaria and Pruritis
- Specialty: Allergy / Pulmonary Diseases | Dermatology | Pharmacology / Toxicology | Radiology / Nuclear Medicine / Radiation Oncology
To Learn More
To view pediatric review articles on this topic from the past year check PubMed.
Evidence-based medicine information on this topic can be found at SearchingPediatrics.com, the National Guideline Clearinghouse and the Cochrane Database of Systematic Reviews.
Information prescriptions for patients can be found at MedlinePlus for these topics: Itching and Skin Pigmentation Disorders.
To view current news articles on this topic check Google News.
To view images related to this topic check Google Images.
Brockow K. Urticaria pigmentosa.
Immunol Allergy Clin North Am. 2004 May;24(2):287-316, vii.
Shaffer HC, Parsons DJ, Peden DB, Morrell D. Recurrent syncope and anaphylaxis as presentation of systemic mastocytosis in a pediatric patient: case report and literature review.
J Am Acad Dermatol. 2006 May;54(5 Suppl):S210-3.
ACGME Competencies Highlighted by Case
1. When interacting with patients and their families, the health care professional communicates effectively and demonstrates caring and respectful behaviors.
2. Essential and accurate information about the patients’ is gathered.
3. Informed decisions about diagnostic and therapeutic interventions based on patient information and preferences, up-to-date scientific evidence, and clinical judgment is made.
4. Patient management plans are developed and carried out.
5. Patients and their families are counseled and educated.
8. Health care services aimed at preventing health problems or maintaining health are provided.
9. Patient-focused care is provided by working with health care professionals, including those from other disciplines.
10. An investigatory and analytic thinking approach to the clinical situation is demonstrated.
11. Basic and clinically supportive sciences appropriate to their discipline are known and applied.
13. Information about other populations of patients, especially the larger population from which this patient is drawn, is obtained and used.
24. Cost-effective health care and resource allocation that does not compromise quality of care is practiced.
25. Quality patient care and assisting patients in dealing with system complexities is advocated.
Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa Children’s Hospital