Cutaneous mastocytosis in a 3-month-old girl

Author: B. Chahine, M.D., Allergist/Immunologist
Reviewer: V. Dimov, M.D., Allergist/Immunologist

A 3-month AAF presented to the hospital with a persistent rash that started at 2 weeks of age. The rash started on the neck and was described as ‘fluid filled blisters that burst and spread to other parts of the body’. Her pediatrician treated her empirically for scabies without improvement.

Associated with her progressive skin lesions, was a low-grade fever of 100-100.4 F. She returned to her PCP who treated her for impetigo but the antibiotic therapy did not resolve her progressive rash, and therefore was she referred to the hospital.

Past medical history (PMH)

GERD. Born at term, 6 lbs 2 oz, vaginal delivery without complications. Tolerating cow milk formula since birth. Immunizations: Received her Hep. B at birth. Her 2 mo. vaccines were deferred due to the rash.


Zantac po, Permethrin topical, Clindamycin po, Altebax topical ointment.

Social history (SH)

Lives with her mother, mat. GM and brother. No sick contacts, no pets. No smoking exposure.

No tobacco or alcohol use.

Family history (FH)

The mother is 20 yo, infected with HPV and has an abnormal pap smear. No other illnesses or STD. The father and paternal GM have SLE. Her brother is a healthy 4-year-old.

Physical examination

Gen: Alert well fed baby, healthy appearing, in no discomfort.
ENT: no scleral icterus, no conjunctival injection. No nasal mucosal edema. Tonsils present, no hypertrophy, no exudates.
Chest: CTA bl, RRR.
Abdomen: Soft, no distension, + BS, no organomegaly. Small reducible periumbilical hernia.
Skin: Bullous 0.5-1 cm lesions in multiple stages of healing involving face trunk and extremities. Ruptured hyperpigmented lesions healing without evidence of superinfection.

What laboratory tests would you order?

CBCD, CMP, Blood cx, HSV titers and VZV titers were all normal.

What happened?

The patient was placed in isolation and started on empiric treatment with Acyclovir for HSV. Her rubtured bullae were treated with topical antibiotics. She was started on antihistamines for her pruritis. Skin biopsy and Tzanck test performed.

What happened next?

Skin biopsy showed cutaneous (bullous) mastocytosis.

Final diagnosis

Cutaneous mastocytosis


Mastocytosis is characterized by an excessive number of apparently normal mast cells in the skin and, occasionally, in other organs. Characteristic skin lesions, called urticaria pigmentosa, are present in most patients, but clinical presentation can vary from a pruritic rash to unexplained collapse and sudden death. These lesions are typically tan to red-brown macules that appear on the trunk and spread symmetrically. Patients with mastocytosis often have a long history of chronic and acute symptoms that were unrecognized as mastocytosis. Skin lesions may or may not accompany systemic mastocytosis. Systemic disease may involve the gastrointestinal tract, the bone marrow or other organs.

Drug therapy is initiated to stabilize mast cell membranes, to reduce the severity of the attacks and to block the action of inflammatory mediators.

Mastocytosis should be suspected and the diagnostic criteria applied in patients without skin lesions if one or more of the following features is present: unexplained ulcer disease ormalabsorption, radiographic or technetium 99 bone scan abnormalities, hepatomegaly, splenomegaly, lymphadenopathy, peripheral blood abnormalities, and unexplained flushing or anaphylaxis. Elevations in the levels of plasma or urinary histamine, or histamine metabolites, urine prostaglandin D2 metabolites, plasma thromboxane B2, plasma (total) mast cell tryptase, or IL-6 are not definitive diagnostic findings, but are consistent with the diagnosis of mastocytosis

A principal objective of treatment in all categories of mastocytosis is the control of mast cell mediator-induced signs and symptoms. The mainstay of therapy is histamine H1 and H2 blockers and the avoidance of triggering factors such as minor skin trauma, hot or cold water that can lead to massive systemic histamine release and systemic symptoms.

Most prominent among these are systemic hypotension, gastric hypersecretion, GI cramping, and pruritus.

H1-receptor antagonists such as the classic antihistamine hydroxyzine, or non-sedating antihistamines such as loratadine or fexofenadine, are instituted to reduce pruritus and flushing. If this is insufficient, the addition of an H2 antagonist, such as ranitidine, cimetidine or famotidine, may be beneficial. One approach is to administer a non-sedating antihistamine during the day, and a potent sedating antihistamine at bedtime. Even with these medications, many patients continue to complain of musculoskeletal pain, headaches, and flushing, in part because of the inability of histamine antagonists to block the effects of high levels of histamine and because of the presence of other mast cell mediators. There may thus be some value in adding aleukotriene-modifying agent.

Disodium cromoglycate (cromolyn sodium) inhibits degranulation of mast cells and has some efficacy in mastocytosis, particularly in the relief of GI complaints.

Epinephrine is used to treat episodes of systemic hypotension. Patients should be taught to administer this medication themselves. If subcutaneous epinephrine is inadequate, intensive therapy for systemic hypotension, as for anaphylaxis, should be instituted. Patients with recurrent episodes of hypotension may be given H1 or H2 antihistamines to reduce the severity of attacks. Episodes of profound hypotension may be spontaneous but have also been observed after insect stings and administration of contrast media.


Mastocytosis. eMedicine Specialties > Dermatology > Benign Neoplasms, 2008.
Cutaneous and Systemic Manifestations of Mastocytosis. AFP, 1999.
Mastocytosis. Merck Manual.
Middleton's Allergy: Principles and Practice, 7th ed (chapter 60).
Mastocytosis in Children Is Associated with Mutations in c-KIT. Nature, 2010.
Neuropeptide blood levels correlate with mast cell load in patients with mastocytosis
Mastocytosis. NEJM blog, 2011.
Mastocytosis - Where are we now? World Allergy Organization summary, 2012.
Proposed diagnostic algorithm for patients with suspected mastocytosis. Allergy, 2014

Mast Cell Disorders (presentation on Google drive):

Published: 03/24/2009
Updated: 03/12/2012

No comments: