Pediatric Dermatology Consult - December 2015

Ancillary testing

Complete blood count showed leukocytosis (13.1 th/mcL), with normal differential. The C-reactive protein was elevated (10 mg/dL). The comprehensive metabolic panel was within normal limits. Mycoplasma pneumoniae antibody, IgM was positive, and herpes virus cultures were negative. The chest x-ray showed a dense right upper lobe airspace opacity, concerning for pneumonia, likely with a component of atelectasis.

Discussion

Mycoplasma pneumoniae–induced rash and mucositis (MIRM) is a syndrome of mucocutaneous involvement in conjunction with an M. pneumoniae infection. M. pneumoniae is a bacteria that commonly causes respiratory tract infections. In children, it is a leading cause of atypical pneumonia.^1,2 Extrapulmonary manifestations are common and can involve the skin, heart, kidneys, gastrointestinal system, and nervous system.³ There is a 1-3 week incubation period for infections, which always begin with respiratory symptoms. The most common early symptoms of this infection are cough, malaise, fever, and headaches. Studies show that between 25%-38% of M. pneumoniae infections have mucocutaneous manifestations.^3,4

An overwhelming majority of cases have mucosal involvement while the degree of skin involvement varies. Cutaneous manifestations, which are usually polymorphic, present with vesiculobullous lesions, targetoid macules and papules, or morbilliform eruptions.³ MIRM is seen most often in children and adolescents, but a few adult cases have been reported. About 66% of cases are seen in males, but the reason for this gender predilection is not well understood.3 Overall, MIRM has an excellent prognosis, compared with the other disorders on the differential diagnosis.

Differential diagnosis

MIRM used to be considered along the spectrum of bullous diseases that have mucosal involvement including erythema multiforme (EM), Stevens-Johnson syndrome (SJS), and toxic epidermal necrosis (TEN).^3-6 The distinction can be difficult to identify, given the similarities that all of these diseases share, and many published articles referencing cases of SJS, TEN, and EM actually fit the criteria for MIRM.6 What sets MIRM apart is the predominance of mucosal involvement with minimal skin involvement and the overwhelming overall good prognosis compared with drug induced SJS.³

Although rare cases have moderate cutaneous involvement, MIRM is most notable for oral lesions, which include ulcers, erosions, and vesiculobullae of the lips and buccal mucosa, as well as ocular and genital mucosal involvement in a lower degree.³ For cases with moderate or even mild involvement of the skin, ruling out other diagnoses becomes more difficult, especially since the dermatologic manifestations of targetoid papules and bullae are common to all of them. Testing for M. pneumoniae will strengthen the diagnosis and can be done in a number of ways. Using polymerase chain reaction to measure for M. pneumoniae DNA offers the benefit of being able to detect an infection early in its course because it does not rely on antibody formation.⁴ Other testing methods include M. pneumoniae antigen detection, and IgM or IgG titers.⁴

Treatment

The mainstay of treatment of this bacterial infection is, of course, antibiotics. Azithromycin and erythromycin are the drugs of choice for children. While tetracyclines and fluoroquinolones can be used to treat M. pneumoniae, their use is not recommended in young children.⁴ Systemic corticosteroids can be used in addition to antibiotics, but there is limited data to support its efficacy in these patients.⁷ In milder cases, reports have documented that the course can be self-limited and may improve with only supportive care. Because of the severity of mucosal involvement in some cases, such as the one in our patient, supportive care may include intravenous hydration and total parenteral nutrition if the patient is unable to tolerate oral intake. In more severe cases, IVIG can be beneficial.8 This has been shown to induce rapid improvement in refractory mucositis when antibiotics and supportive mucosal care alone have not been sufficient.⁸

References

1. (J Clin Microbiol. 2015 Jan;53[1]:124-30.)
2. (Clin Microbiol. 2004;17[4]:697-728.)
3. (J Am Acad Dermatol.  2015;72[2]: 239-54.)
4. (Int J Dermatol. 2009 Jul;48[7]:673-80.)  
5. (J Eur Acad Dermatol Venereol. 2015 Mar;29[3]:595-8.)  
6. (J Am Acad Dermatol. 2005 Feb;52[2]:312-5.)
7. (Pediatr Dermatol. 2014 Nov-Dec;31[6]:664-9.)
8. (Acta Paediatr. 2011 Nov;100[11]:e238-40.)

Dr. Matiz is assistant professor of dermatology at Rady Children’s Hospital San Diego–University of California San Diego and Mr. Ginsberg is a research associate at the hospital. They said they had no relevant financial disclosures.

Email them at [email protected].

Ancillary testing

Complete blood count showed leukocytosis (13.1 th/mcL), with normal differential. The C-reactive protein was elevated (10 mg/dL). The comprehensive metabolic panel was within normal limits. Mycoplasma pneumoniae antibody, IgM was positive, and herpes virus cultures were negative. The chest x-ray showed a dense right upper lobe airspace opacity, concerning for pneumonia, likely with a component of atelectasis.

Discussion

Mycoplasma pneumoniae–induced rash and mucositis (MIRM) is a syndrome of mucocutaneous involvement in conjunction with an M. pneumoniae infection. M. pneumoniae is a bacteria that commonly causes respiratory tract infections. In children, it is a leading cause of atypical pneumonia.^1,2 Extrapulmonary manifestations are common and can involve the skin, heart, kidneys, gastrointestinal system, and nervous system.³ There is a 1-3 week incubation period for infections, which always begin with respiratory symptoms. The most common early symptoms of this infection are cough, malaise, fever, and headaches. Studies show that between 25%-38% of M. pneumoniae infections have mucocutaneous manifestations.^3,4

An overwhelming majority of cases have mucosal involvement while the degree of skin involvement varies. Cutaneous manifestations, which are usually polymorphic, present with vesiculobullous lesions, targetoid macules and papules, or morbilliform eruptions.³ MIRM is seen most often in children and adolescents, but a few adult cases have been reported. About 66% of cases are seen in males, but the reason for this gender predilection is not well understood.3 Overall, MIRM has an excellent prognosis, compared with the other disorders on the differential diagnosis.

Differential diagnosis

MIRM used to be considered along the spectrum of bullous diseases that have mucosal involvement including erythema multiforme (EM), Stevens-Johnson syndrome (SJS), and toxic epidermal necrosis (TEN).^3-6 The distinction can be difficult to identify, given the similarities that all of these diseases share, and many published articles referencing cases of SJS, TEN, and EM actually fit the criteria for MIRM.6 What sets MIRM apart is the predominance of mucosal involvement with minimal skin involvement and the overwhelming overall good prognosis compared with drug induced SJS.³

Although rare cases have moderate cutaneous involvement, MIRM is most notable for oral lesions, which include ulcers, erosions, and vesiculobullae of the lips and buccal mucosa, as well as ocular and genital mucosal involvement in a lower degree.³ For cases with moderate or even mild involvement of the skin, ruling out other diagnoses becomes more difficult, especially since the dermatologic manifestations of targetoid papules and bullae are common to all of them. Testing for M. pneumoniae will strengthen the diagnosis and can be done in a number of ways. Using polymerase chain reaction to measure for M. pneumoniae DNA offers the benefit of being able to detect an infection early in its course because it does not rely on antibody formation.⁴ Other testing methods include M. pneumoniae antigen detection, and IgM or IgG titers.⁴

Treatment

The mainstay of treatment of this bacterial infection is, of course, antibiotics. Azithromycin and erythromycin are the drugs of choice for children. While tetracyclines and fluoroquinolones can be used to treat M. pneumoniae, their use is not recommended in young children.⁴ Systemic corticosteroids can be used in addition to antibiotics, but there is limited data to support its efficacy in these patients.⁷ In milder cases, reports have documented that the course can be self-limited and may improve with only supportive care. Because of the severity of mucosal involvement in some cases, such as the one in our patient, supportive care may include intravenous hydration and total parenteral nutrition if the patient is unable to tolerate oral intake. In more severe cases, IVIG can be beneficial.8 This has been shown to induce rapid improvement in refractory mucositis when antibiotics and supportive mucosal care alone have not been sufficient.⁸

References

1. (J Clin Microbiol. 2015 Jan;53[1]:124-30.)
2. (Clin Microbiol. 2004;17[4]:697-728.)
3. (J Am Acad Dermatol.  2015;72[2]: 239-54.)
4. (Int J Dermatol. 2009 Jul;48[7]:673-80.)  
5. (J Eur Acad Dermatol Venereol. 2015 Mar;29[3]:595-8.)  
6. (J Am Acad Dermatol. 2005 Feb;52[2]:312-5.)
7. (Pediatr Dermatol. 2014 Nov-Dec;31[6]:664-9.)
8. (Acta Paediatr. 2011 Nov;100[11]:e238-40.)

Dr. Matiz is assistant professor of dermatology at Rady Children’s Hospital San Diego–University of California San Diego and Mr. Ginsberg is a research associate at the hospital. They said they had no relevant financial disclosures.

Email them at [email protected].

Ancillary testing

Complete blood count showed leukocytosis (13.1 th/mcL), with normal differential. The C-reactive protein was elevated (10 mg/dL). The comprehensive metabolic panel was within normal limits. Mycoplasma pneumoniae antibody, IgM was positive, and herpes virus cultures were negative. The chest x-ray showed a dense right upper lobe airspace opacity, concerning for pneumonia, likely with a component of atelectasis.

Discussion

Mycoplasma pneumoniae–induced rash and mucositis (MIRM) is a syndrome of mucocutaneous involvement in conjunction with an M. pneumoniae infection. M. pneumoniae is a bacteria that commonly causes respiratory tract infections. In children, it is a leading cause of atypical pneumonia.^1,2 Extrapulmonary manifestations are common and can involve the skin, heart, kidneys, gastrointestinal system, and nervous system.³ There is a 1-3 week incubation period for infections, which always begin with respiratory symptoms. The most common early symptoms of this infection are cough, malaise, fever, and headaches. Studies show that between 25%-38% of M. pneumoniae infections have mucocutaneous manifestations.^3,4

An overwhelming majority of cases have mucosal involvement while the degree of skin involvement varies. Cutaneous manifestations, which are usually polymorphic, present with vesiculobullous lesions, targetoid macules and papules, or morbilliform eruptions.³ MIRM is seen most often in children and adolescents, but a few adult cases have been reported. About 66% of cases are seen in males, but the reason for this gender predilection is not well understood.3 Overall, MIRM has an excellent prognosis, compared with the other disorders on the differential diagnosis.

Differential diagnosis

MIRM used to be considered along the spectrum of bullous diseases that have mucosal involvement including erythema multiforme (EM), Stevens-Johnson syndrome (SJS), and toxic epidermal necrosis (TEN).^3-6 The distinction can be difficult to identify, given the similarities that all of these diseases share, and many published articles referencing cases of SJS, TEN, and EM actually fit the criteria for MIRM.6 What sets MIRM apart is the predominance of mucosal involvement with minimal skin involvement and the overwhelming overall good prognosis compared with drug induced SJS.³

Although rare cases have moderate cutaneous involvement, MIRM is most notable for oral lesions, which include ulcers, erosions, and vesiculobullae of the lips and buccal mucosa, as well as ocular and genital mucosal involvement in a lower degree.³ For cases with moderate or even mild involvement of the skin, ruling out other diagnoses becomes more difficult, especially since the dermatologic manifestations of targetoid papules and bullae are common to all of them. Testing for M. pneumoniae will strengthen the diagnosis and can be done in a number of ways. Using polymerase chain reaction to measure for M. pneumoniae DNA offers the benefit of being able to detect an infection early in its course because it does not rely on antibody formation.⁴ Other testing methods include M. pneumoniae antigen detection, and IgM or IgG titers.⁴

Treatment

The mainstay of treatment of this bacterial infection is, of course, antibiotics. Azithromycin and erythromycin are the drugs of choice for children. While tetracyclines and fluoroquinolones can be used to treat M. pneumoniae, their use is not recommended in young children.⁴ Systemic corticosteroids can be used in addition to antibiotics, but there is limited data to support its efficacy in these patients.⁷ In milder cases, reports have documented that the course can be self-limited and may improve with only supportive care. Because of the severity of mucosal involvement in some cases, such as the one in our patient, supportive care may include intravenous hydration and total parenteral nutrition if the patient is unable to tolerate oral intake. In more severe cases, IVIG can be beneficial.8 This has been shown to induce rapid improvement in refractory mucositis when antibiotics and supportive mucosal care alone have not been sufficient.⁸

References

1. (J Clin Microbiol. 2015 Jan;53[1]:124-30.)
2. (Clin Microbiol. 2004;17[4]:697-728.)
3. (J Am Acad Dermatol.  2015;72[2]: 239-54.)
4. (Int J Dermatol. 2009 Jul;48[7]:673-80.)  
5. (J Eur Acad Dermatol Venereol. 2015 Mar;29[3]:595-8.)  
6. (J Am Acad Dermatol. 2005 Feb;52[2]:312-5.)
7. (Pediatr Dermatol. 2014 Nov-Dec;31[6]:664-9.)
8. (Acta Paediatr. 2011 Nov;100[11]:e238-40.)

Dr. Matiz is assistant professor of dermatology at Rady Children’s Hospital San Diego–University of California San Diego and Mr. Ginsberg is a research associate at the hospital. They said they had no relevant financial disclosures.

Email them at [email protected].