Hemoglobinopathies are a group of hereditary diseases first described in 1910 by Herrick when investigating black patients with the disease who had anemia, abdominal pain and joint pain  .
Among hemoglobinopathies, the most prevalent in our population are hemoglobins S and C, which are capable of producing disease when homozygous. However, when heterozygous, the carrier is clinically asymptomatic, showing no disease and no anemia  .
Sickle cell anemia affects about 100,000 individuals in the United States, and approximately two million Americans carry the sickle cell trait  . A recent study estimated that about 305,800 babies were born with Sickle Cell Anemia in 2010, of which two-thirds were in Africa. The outlook is that, on average, there is an increase of 25% of cases, reaching a total of 404,200 individuals in 2050  .
Inheriting the Sickle Cell Anemia gene from both parents results in homozygous (SS) sickle cell disease which is usually severe  . Hemoglobinopathy C is considered a benign condition. However, there is evidence that this pathology can cause serious problems  . In cases of double heterozygotes with sickle hemoglobin C (SC), the disease is less expressive in its clinical condition  and rarer.
Therefore, due to the rarity of the nosological entity and its importance to the academic community, it was aimed to discuss a case of patient affected by SC Hemoglobinopathy, who presented osteomyelitis and septic arthritis.
2. Case Report
S.L.B, 04 years and 04 months, male, black, born and raised from Barbalha, in the state of Ceará, Brazilian Northeast, previously diagnosed with SC hemoglobinopathy, septic arthritis and chronic osteomyelitis in the right knee.
Neonatal history: born cesarean birth, and then phototherapy for 2 hours. Exclusive breastfeeding up to six months and mixed up to 03 years. Vaccination scheme as recommended by the Brazilian Ministry of Health, without presenting any reactions. Development Neuropsychomotor (DPNM) suitable for age. Parents have no history of consanguinity.
Patient has a previous hospitalization with pain in the joints in knee and hip and several febrile peaks. Upon physical examination, the patient had difficulty walking, without edema, pedal and tibial posterior pulses present, with no signs of compartment syndrome. He used Cephalotin for seven days, was released home with Cephalexin for 10 days. There was no improvement in the febrile condition and it evolved with phlogistic signs in the right knee.
Returned to service with maintenance of clinical and RX showing important osteomyelitis in his right knee (Figure 1). Complementary exams revealed anemia, leukocytosis and lymphopenia in hemogram (HMG) of admission (November 4st, 2016). And the right knee Ultrasonography (USG) performed at admission evidenced joint cavity with irregular and thickened cartilage with a discrete fluid collection compatible with right knee arthritis.
The treatment with antibiotic therapy according to the protocol (Oxacillin and Ceftriaxone) was restarted and submitted to joint drainage in affected limb. It evolved with episodes of intense pain in the right knee that improved to the use of Tramadol and progressively were diminishing throughout the hospitalization. After the initiation of treatment was observed improvement hematimetric patterns (Table 1), the hemoglobin electrophoresis pattern (Table 2), the ESR and CRP (Table 3).
Figure 1. RX showing important osteomyelitis in his right knee.
Table 1. Serial Hemograms (cel/mm3).
Legend: Leuco―Leukocytes. Neut―Neutrophilis. Seg―Segmented. Eos―Eosinophils. Bast―Blood Counts. Linf―Lymphocytes. Mon―Monocytes. Plt― Platelets. Hb―Hemoglobin. Ht―Hematocrit. Hem―Red blood cells. VCM―Mean corpuscular volume. HCM―Corpuscular Hemoglobin Concentration. CHCM―Mean corpuscular hemoglobin concentration. RDW―Red Cell Distribution Width.
Table 2. Hemoglobin Electrophoresis.
Legend: Fetal portion of hemoglobin (F); A1 portion of Hemoglobin (A1); A2 portion of hemoglobin (A2); S portion of hemoglobin (S); C portion of Hemoglobin (C).
Table 3. Laboratory Exams and their dates.
Legend: Hemosedimentation volume (HSV); C Reactive Protein (CRP); Total Bilirubin (TB); Direct Bilirubin (DB); Indirect Bilirubin (IB).
Patient was discharged after completion of antibiotic therapy and clinical improvement, being able to return to their activities.
Sickle cell disease is a group of genetic diseases that is especially prevalent in tropical and subtropical regions  caused by inheritance of HBB mutations due to sickle hemoglobin (HbS mutation, HBB E6V) in homozygous form (Sickle Cell Anemia, HbSS) or as a composite heterozygote with another abnormal hemoglobin (e.g. HbSC, HbSβtalh)  .
Forced migration and the continuous movement of the population have spread throughout the world, with birth rates estimated at 0.49 per 1000 in the Americas, 0.07 per 1000 in Europe, 0.68 per 1000 in South and Southeast Asia and 10.68 per 1000 in Africa  . The prevalence of hereditary anemias in the population varies among Brazilian regions, since it is closely linked to the process of ethnic formation of each one  .
Studies in Brazil show the high prevalence of heterozygotes for HbS and HbC  , especially in Afro-descendants ranging from 6.9% to 14.5%   . This is in accordance with this case.
In 1987, the largest study of prevalence and distribution of hemoglobinopathies in Brazil showed that 74.12% of the sample population had HbAS, HbSS or HbSC mutation  . In the State of Pernambuco, Brazil, it was observed that 0.6% of the infants analyzed had HbAC and 5.3% presented Hb S; of this last percentage, 97.1% had HbAS and 2.9% had HbSC  .
Typically, HbSC disease is similar to sickle cell disease (Squires, 2016) characterized by chronic anemia and vaso-occlusive and hemolytic complications acute and chronic  . Examples of such complications are pain or vaso-occlusive crises, aplastic crisis, cutaneous pallor, jaundice, chronic anemia, hand-foot syndrome, ulcers in the lower limbs, splenic sequestration, with increased amount of blood in the liver and spleen, which leads to a decrease in circulating blood volume  .
However, these manifestations are milder and have a lower frequency, which gives HbSC patients a longer life expectancy  . It is interesting to note that septic arthritis or even osteomyelitis itself are not often cited as direct and common consequences of HbSC, giving the case an interesting aspect to the study. In 2012, a study carried out at the Escola Paulista de Medicina, São Paulo, Brazil, reports three cases in a sample of 21 patients presenting hemoglobinopathy as the underlying disease of bone infections  .
Osteonecrosis, especially in the shoulder, occurs with almost equal frequency between HbSC and HBSS and the Acute Thoracic Syndrome (ATS) and may have increased mortality in HbSC disease  . Aseptic necrosis of the femoral head is related to episodes of acute thoracic syndrome due to fatty embolism  , justifying the importance in the diagnosis of heterozygous individuals  . It is emphasized, however, that even in the case of adequate diagnosis and treatment, factors such as antimicrobial resistance and non-adherence therapy may disrupt the patient's conduction, in our report the first cause is the most likely associated with an inherent difficulty in the process infectious. According to Puccini, Ferrarini and Iazzetti  bone infections in the pediatric age group should always be treated as severe and, even when appropriate therapy can still evolve with sequelae.
There is no specific treatment and, therefore, the approach to reduce mortality and morbidity of the disease should be based on the prevention of complications such as pain, infections, splenic sequestration and multiprofessional follow-up with early diagnosis through neonatal screening   included in the National Neonatal Screening Program (NNSP), through Administrative Rule nº 822/01, of the Brazilian Ministry of Health   .
4. Final Considerations
Hemoglobinopathy SC is a disease that can present high morbidity, especially when it comes to osteoarticular infections although not very high prevalence. Thus, osteomyelitis and septic arthritis in patients in the pediatric age group should be considered as serious infections that deserve hospitalization and more expressive treatment.